var btn_p_ary = ["btn_brand_r.jpg","btn_design_r.jpg","btn_shiyou_r.jpg","btn_sample_r.jpg"];

function performance_init(){
	for(var cnt = 0; cnt < btn_p_ary.length; cnt++){
		var imgObj = new Image();
		imgObj.src = "images/performance_common/"+btn_p_ary[cnt];
	}
}

function onPerformanceLoad( aID )
{
	var imgObj = document.getElementById( aID );
	imgObj.src = "images/performance_common/"+aID+"_r.jpg";
}

function offPerformanceLoad( aID )
{
	var imgObj = document.getElementById( aID );
	imgObj.src = "images/performance_common/"+aID+".jpg";
}

performance_init();