function fillCategory(id){
	if(id == '1'){
		addOption(document.dualregistration.TermType1, "Semester", "Semester", "");
		addOption(document.dualregistration.TermType1, "Quarter", "Quarter", "");
	}
	if(id == '2'){
		addOption(document.dualregistration.TermType1, "Semester", "Semester", "");
		addOption(document.dualregistration.TermType1, "Quarter", "Quarter", "");
		addOption(document.dualregistration.TermType2, "Semester", "Semester", "");
		addOption(document.dualregistration.TermType2, "Quarter", "Quarter", "");
	}
	if(id == '3'){
		addOption(document.dualregistration.TermType1, "Semester", "Semester", "");
		addOption(document.dualregistration.TermType1, "Quarter", "Quarter", "");
		addOption(document.dualregistration.TermType2, "Semester", "Semester", "");
		addOption(document.dualregistration.TermType2, "Quarter", "Quarter", "");
		addOption(document.dualregistration.TermType3, "Semester", "Semester", "");
		addOption(document.dualregistration.TermType3, "Quarter", "Quarter", "");
	}
	if(id == '4'){
		addOption(document.dualregistration.TermType1, "Semester", "Semester", "");
		addOption(document.dualregistration.TermType1, "Quarter", "Quarter", "");
		addOption(document.dualregistration.TermType2, "Semester", "Semester", "");
		addOption(document.dualregistration.TermType2, "Quarter", "Quarter", "");
		addOption(document.dualregistration.TermType3, "Semester", "Semester", "");
		addOption(document.dualregistration.TermType3, "Quarter", "Quarter", "");
		addOption(document.dualregistration.TermType4, "Semester", "Semester", "");
		addOption(document.dualregistration.TermType4, "Quarter", "Quarter", "");
	}
}

function SelectSubCat(id){
	if(id == '1'){
		removeAllOptions(document.dualregistration.Term1);
		addOption(document.dualregistration.Term1, "Select Term", "Select Term", "");

		if(document.dualregistration.TermType1.value == 'Semester'){
			addOption(document.dualregistration.Term1,"Spring", "Spring", "");
			addOption(document.dualregistration.Term1,"Summer", "Summer", "");
			addOption(document.dualregistration.Term1,"Fall", "Fall", "");
		}
		if(document.dualregistration.TermType1.value == 'Quarter'){
			addOption(document.dualregistration.Term1,"Winter", "Winter", "");
			addOption(document.dualregistration.Term1,"Spring", "Spring", "");
			addOption(document.dualregistration.Term1,"Summer", "Summer", "");
			addOption(document.dualregistration.Term1,"Fall", "Fall", "");
		}
	}
	if(id == '2'){
		removeAllOptions(document.dualregistration.Term2);
		addOption(document.dualregistration.Term2, "Select Term", "Select Term", "");

		if(document.dualregistration.TermType2.value == 'Semester'){
			addOption(document.dualregistration.Term2,"Spring", "Spring", "");
			addOption(document.dualregistration.Term2,"Summer", "Summer", "");
			addOption(document.dualregistration.Term2,"Fall", "Fall", "");
		}
		if(document.dualregistration.TermType2.value == 'Quarter'){
			addOption(document.dualregistration.Term2,"Winter", "Winter", "");
			addOption(document.dualregistration.Term2,"Spring", "Spring", "");
			addOption(document.dualregistration.Term2,"Summer", "Summer", "");
			addOption(document.dualregistration.Term2,"Fall", "Fall", "");
		}
	}
	if(id == '3'){
		removeAllOptions(document.dualregistration.Term3);
		addOption(document.dualregistration.Term3, "Select Term", "Select Term", "");

		if(document.dualregistration.TermType3.value == 'Semester'){
			addOption(document.dualregistration.Term3,"Spring", "Spring", "");
			addOption(document.dualregistration.Term3,"Summer", "Summer", "");
			addOption(document.dualregistration.Term3,"Fall", "Fall", "");
		}
		if(document.dualregistration.TermType3.value == 'Quarter'){
			addOption(document.dualregistration.Term3,"Winter", "Winter", "");
			addOption(document.dualregistration.Term3,"Spring", "Spring", "");
			addOption(document.dualregistration.Term3,"Summer", "Summer", "");
			addOption(document.dualregistration.Term3,"Fall", "Fall", "");
		}
	}
	if(id == '4'){
		removeAllOptions(document.dualregistration.Term4);
		addOption(document.dualregistration.Term4, "Select Term", "Select Term", "");

		if(document.dualregistration.TermType4.value == 'Semester'){
			addOption(document.dualregistration.Term4,"Spring", "Spring", "");
			addOption(document.dualregistration.Term4,"Summer", "Summer", "");
			addOption(document.dualregistration.Term4,"Fall", "Fall", "");
		}
		if(document.dualregistration.TermType4.value == 'Quarter'){
			addOption(document.dualregistration.Term4,"Winter", "Winter", "");
			addOption(document.dualregistration.Term4,"Spring", "Spring", "");
			addOption(document.dualregistration.Term4,"Summer", "Summer", "");
			addOption(document.dualregistration.Term4,"Fall", "Fall", "");
		}
	}
}

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);
}