function fillSystems(){ 
 // this function is used to fill the Systems list on load first is value, second is text 
addOption(document.drop_list_audSystems.Systems, "Floor", "Floor Racks", "");
addOption(document.drop_list_audSystems.Systems, "Seismic-certified", "Seismic-Certified RacksTM", "");
addOption(document.drop_list_audSystems.Systems, "Vari-Rack", "Vari-Rack", "");
addOption(document.drop_list_audSystems.Systems, "Portable", "Portable Racks", "");
addOption(document.drop_list_audSystems.Systems, "Wall-Mount", "Wall-Mount Racks & Shelves", "");
addOption(document.drop_list_audSystems.Systems, "Pull", "Pull & Turn Racks", "");
addOption(document.drop_list_audSystems.Systems, "Credenza", "Credenza Racks", "");
addOption(document.drop_list_audSystems.Systems, "Laminated", "Laminated Racks", "");
}

function SelectSubCat_audSystems(){
// ON selection of loads this function will work

removeAllOptions(document.drop_list_audSystems.SubCat_audSystems);
removeAllOptions(document.drop_list_audSystems.Tier3_audSystems);
addOption(document.drop_list_audSystems.SubCat_audSystems, "", "Make a Selection", "");

if(document.drop_list_audSystems.Systems.value == 'audio1T1'){
addOption(document.drop_list_audSystems.SubCat_audSystems,"audio2T1","12\" iMount\u00AE Pro-Sound");
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T2"	,"	12\" MDX Pro	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T3"	,"	10\" iMount\u00AE Pro-Sound	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T4"	,"	8\" iMount\u00AE Pro-Sound	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T5"	,"	8\" iMount\u00AE Subwoofer	");
}
if(document.drop_list_audSystems.Systems.value == 'audio1T2'){
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T6"	,"	12\" iMount\u00AE Pro-Sound (cylindrical)	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T7"	,"	10\" iMount\u00AE Pro-Sound (cylindrical)	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T8"	,"	8\"  iMount\u00AE Pro-Sound (cylindrical)	");
}
if(document.drop_list_audSystems.Systems.value == 'audio1T3'){
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T9"	,"	8\" LT Pro	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T10"	,"	8\" LT Music/Paging	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T11"	,"	6\" LT Pro	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T12"	,"	4\" LT Pro	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T13"	,"	4\" LT Music/Paging	");

}
if(document.drop_list_audSystems.Systems.value == 'audio1T4'){
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T14"	,"	8\" CN Pro	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T15"	,"	8\" CN Pro Extended Lip	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T16"	,"	6\" CN Pro	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T17"	,"	6\" CN Pro Extended Lip	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,	"audio2T18"	,"	R-PAK Music/Paging	");

}
if(document.drop_list_audSystems.Systems.value == 'audio1T5'){
addOption(document.drop_list_audSystems.SubCat_audSystems	,"audio2T19","	OS High-Fidelity Indoor/Outdoor	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,"audio2T20","	DSL Music/Paging 	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,"audio2T21","	DSQ Music/Paging	");
addOption(document.drop_list_audSystems.SubCat_audSystems	,"audio2T22","	SL Music/Paging 	");
}
if(document.drop_list_audSystems.Systems.value == 'audio1T6'){
addOption(document.drop_list_audSystems.SubCat_audSystems,"audio2T23", "BC Music/Paging");
}
if(document.drop_list_audSystems.Systems.value == 'audio1T7'){
addOption(document.drop_list_audSystems.SubCat_audSystems,"audio2T24", "Unihorn\u00AE Paging");
addOption(document.drop_list_audSystems.SubCat_audSystems,"audio2T25", "Paging Horns");
}
}
////////////////// 
function SelectTier3_audSystems(){
removeAllOptions(document.drop_list_audSystems.Tier3_audSystems);
addOption(document.drop_list_audSystems.Tier3_audSystems, "", "Make a Selection", "");


if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T1'){	
addOption(document.drop_list_audSystems.Tier3_audSystems	,"audio3T1","	3 cu ft / 250W	");
addOption(document.drop_list_audSystems.Tier3_audSystems	,"audio3T2","	3 cu ft / 150W	");
addOption(document.drop_list_audSystems.Tier3_audSystems	,"audio3T3","	2 cu ft / 150W	");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T2'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T4","3 cu ft / 100W");
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T5","2 cu ft / 100W");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T3'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T6","2 cu ft / 125W");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T4'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T7","2 cu ft / 100W");
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T8","2 cu ft / 50W");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T5'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T9","2 cu ft / 100W");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T6'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T10","3 cu ft / 250W");
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T11","3 cu ft / 150W");
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T12","2 cu ft / 250W");
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T13","2 cu ft / 150W");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T7'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T14","2 cu ft / 125W");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T8'){
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T15","2 cu ft / 100W");
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T16","1.25 cu ft / 50W");	
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T9'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T17","0.8 cu ft / 1x2");
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T18","0.8 cu ft / 2x2");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T10'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T19","1x2 (no backbox)");
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T20","0.8 cu ft / 2x2");
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T21","0.15 cu ft / 1x2");
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T22","0.15 cu ft / 2x2");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T11'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T23","0.8 cu ft / 1x2");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T12'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T24","0.8 cu ft / 1x2");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T13'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T25","0.15 cu ft / 1x2");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T14'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T26","0.4 cu ft / 50W");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T15'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T27","0.4 cu ft / 50W");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T16'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T28","0.4 cu ft / 50W");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T17'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T29","0.4 cu ft / 50W");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T18'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T30","0.15 cu ft ");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T19'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T31","Speaker");
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T32","Accessories");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T20'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T33","0.3 cu ft ");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T21'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T34","0.3 cu ft ");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T22'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T35","0.2 cu ft");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T23'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T36","0.15 cu ft ");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T24'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"audio3T37","Unihorn'\u00AE'");
}
if(document.drop_list_audSystems.SubCat_audSystems.value == 'audio2T25'){	
addOption(document.drop_list_audSystems.Tier3_audSystems,"","No further options");
}






}
/////////////////

/////////////////
function removeAllOptions(selectbox)
{
	var i;
	for(i=selectbox.options.length-1;i>=0;i--)
	{
		//selectbox.options.remove(i);
		selectbox.remove(i);
	}
}


function addOption(selectbox, value, text )
{
	var optn = document.createElement("OPTION");
	optn.text = text;
	optn.value = value;

	selectbox.options.add(optn);
}