/**
 * Remove all of the options from the passed <select> object
 *
 * @param selectObject
 */
function clearOptions(selectObject)
{
	if (!selectObject) {
		return;
	}
	
	while (selectObject.options.length>0) {
		selectObject.remove(0);
	}
}

/**
 * Add a name/value option to the passed <select> object
 *
 * @param selectObject
 * @param name
 * @param value
 */
function addOption(selectObject, name, value)
{
	if (!selectObject) {
		return;
	}
	
	selectObject.options[selectObject.options.length] = 
		new Option(name, value);
}

/**
 * Trim leading and trailing whitespace
 *
 * @param str
 */
function trim(str)
{
	if (!str) {
		return "";
	}
	return str.replace(/^\s+|\s+$/g,"");
}

function init()
{    
    $('year').disabled = true;
    clearOptions($('year'));
    addOption($('year'), "Select Year", "");
        
    $('make').disabled = true;
	clearOptions($('make'));
	addOption($('make'), "Select Make", "");	
	
    var url='cfmx/web/tiresel/yearmake.cfm?year=yes';   
    new Ajax.Request(
		    url, {
			method: 'post',			
			onComplete: ts_populateYears }
	);	
	Event.observe( $('year'), 'change', ts_yearChange, false );	
}

function ts_populateYears(response){	
	var resp = response.responseText.evalJSON();		
	var years = resp.data;					
	$('year').disabled = false;	
	clearOptions($('year'));			
	for (var i=0; i<years.length; i++) {	   
		addOption($('year'), years[i].TVEH_YEAR, years[i].TVEH_YEAR);
	}
}

function ts_yearChange() {
	
	$('make').disabled = true;
	clearOptions($('make'));
	addOption($('make'), "Select Make", "");
	
	var make = $F('year');
		
	if (make == "Select Year" || make == "") {
		
		return alert("Please select a year.");				
	}  	
	var url= 'cfmx/web/tiresel/yearmake.cfm?make='+escape(make);        
    new Ajax.Request(
	    url, {
		method: 'post',			
		onComplete: ts_populateMakes }
	);	
		

} // End ts_yearChange().

function ts_populateMakes(response){
	var resp = response.responseText.evalJSON();	
	var makes = resp.data;	
	$('make').disabled = false;
	clearOptions($('make'));
	for (var i=0; i<makes.length; i++) {	    
		addOption($('make'), makes[i].TVEH_MAKE, makes[i].TVEH_MAKE);
	}
}