var store = new Array();
var qtys = new Array();

store[1] = new Array(
'Size: 13','13',  
'Size: 16','16',
'Size: 18','18',
'Size: 19','19',
'Size: 21.5','21.5'
);
qtys[1] = 4;

store[2] = new Array(
'One Size', 'One Size'
);
qtys[2] = 1;

store[3] = new Array(
'N/A', 'N/A'
);
qtys[3] = 1;

store[4] = new Array(
'N/A', 'N/A'
);
qtys[4] = 1;

store[5] = new Array(
'N/A', 'N/A'
);
qtys[5] = 1;

window.addEvent('domready', function(){
	$('hireselection').addEvent('change', updateOptions);
});

function updateOptions() {
	// -- get current value
	var currentSel = $('hireselection').get('value');

	// -- update other options
	for (i = $('hiresize').options.length-1; i >= 0; i--) {
		$('hiresize').remove(i);
	}

	var list = store[currentSel];
	for (i = 0; i < (list.length); i+=2) {
		try {
			$('hiresize').add(new Option(list[i], list[i+1]), null);
		}
		catch (err) {
			$('hiresize').add(new Option(list[i], list[i+1]));
		}		
	}

	for (i = $('hirequantity').options.length-1; i >= 0; i--) {
		$('hirequantity').remove(i);
	}

	for (i = 1; i < (qtys[currentSel] + 1); i++) {
		try {
			$('hirequantity').add(new Option(i, i), null);
		}
		catch (err) {
			$('hirequantity').add(new Option(i, i));
		}		
	}
}