// Generate the Make Dropdown option list.
function updateMakeSelect(makeSel, curMake) {
	makeSel.options.length = 0;
	makeSel.options[0] = new Option("Select Make", "");
	if (! curMake || curMake == "CATS" ) { makeSel.options[0].selected = true; }
	for (var make in cars) {
		if (typeof(make) != "string") { continue; }
		makeSel.options[makeSel.options.length] = new Option(make, make);
		if (curMake == make) {
			makeSel.options[makeSel.options.length-1].selected = true;
		}
	}
}

// Update the Model Dropdown to reflect the selected make. 
function updateModelSelect(modelSel, curMake, curModel) {
	modelSel.options.length = 0;
	modelSel.options[0] = new Option("Select Model", "");
	if (! curModel) { modelSel.options[0].selected = true; }
	modelSel.options[1] = new Option("Any Model", "");
	// Skip null, blank, or Category lookups.
	if (! curMake || ! cars[curMake]) { return; }
	for (var i = 0; i < cars[curMake].length; i++) {
		var model = cars[curMake][i];
		modelSel.options[modelSel.options.length] = new Option(model, model);
		if (curModel == model) {
			modelSel.options[modelSel.options.length-1].selected = true;
		}
	}
}