var mh = 580;
var mw = 910;

function checksize(){
	if(document.body.clientHeight > mh){
		document.getElementById("mainflash").style.height = "100%";
	} else {
		document.getElementById("mainflash").style.height = mh + "px";
	}

	if(document.body.clientWidth > mw){
		document.getElementById("mainflash").style.width = "100%";
	} else {
		document.getElementById("mainflash").style.width = mw + "px";
	}
}
window.onresize = checksize;