$(document).ready(function(){
	var f = document.forms.test_form;
	function q1Change()
	{
		var disabled = true;
		if ( f.question1.value > 0 ) {
			disabled = false;
		}
		f.question2.disabled = disabled;
		f.question3.disabled = disabled;
		f.question5.disabled = disabled;
		f.question6.disabled = disabled;
		if ( disabled ) {
			$(f.question16).attr('disabled',true);
		} else {
			$(f.question16).removeAttr('disabled');
		}
	}

	function q3Change()
	{
		var disabled = true;
		if ( f.question3.value > 0 ) {
			disabled = false;
		}
		f.question4.disabled = disabled;
	}

	function q7Change()
	{
		var disabled = true;
		if ( $(f.question7).filter(':checked').val() === "1" ) {
			disabled = false;
		}
		f.question8.disabled = disabled;
		if ( disabled ) {
			$(f.question9).attr('disabled',true);
		} else {
			$(f.question9).removeAttr('disabled');
		}
	}

	function q12Change()
	{
		var disabled = true;
		if ( $(f.question12).filter(':checked').val() === "1" ) {
			disabled = false;
		}
		f.question13.disabled = disabled;
	}

	function q17Change()
	{
		var disabled = true;
		if ( $(f.question17).filter(':checked').val() === "1" ) {
			disabled = false;
		}
		f.question18.disabled = disabled;
		if ( disabled ) {
			$(f.question19).attr('disabled',true);
		} else {
			$(f.question19).removeAttr('disabled');
		}
	}

	$(f.question1).change(q1Change);
	$(f.question3).change(q3Change);
	$(f.question7).change(q7Change);
	$(f.question12).change(q12Change);
	$(f.question17).change(q17Change);

	q1Change();
	q3Change();
	q7Change();
	q12Change();
	q17Change();
});