function mostrar_modelos()
{
	if (document.getElementById("marca").value != 0)
	{
		var modelRef;
		var formRef;
		var sNewArray = new Array();
	
		sNewArray = eval(eval('make'+document.getElementById("marca").value));
	
		var first = new Array();
		var rest = new Array();
	
		for(i = 0; i < sNewArray.length; i++)
		{
			first[i] = sNewArray[i].substr(0, sNewArray[i].indexOf(":"));
			rest[i]  = sNewArray[i].substr(sNewArray[i].indexOf(":")+1, sNewArray[i].length);
		}
	
		modelRef = document.getElementById("modelo");
		formRef = document.getElementById("modelo");
		formRef.options.length = sNewArray.length;
	
		for(var i = 0; i < sNewArray.length; i++)
		{
			formRef.options[i].text = first[i];
			formRef.options[i].value = rest[i];
		}
		formRef.disabled = false;
		formRef.selectedIndex = 0;
	} else {
		document.getElementById("modelo").disabled = true;
	}
}
function modifica_modelos()
{

}