function centerbox(){
	var winmax= new Array;
	if(typeof( window.innerWidth ) == 'number' ) {
		//Não-IE
		winmax[0] = window.innerWidth;
		winmax[1] = window.innerHeight;
	}else if(document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {
		//IE 6+
		winmax[0] = document.documentElement.clientWidth;
		winmax[1] = document.documentElement.clientHeight;
	}else if(document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
		//IE 4
		winmax[0] = document.body.clientWidth;
		winmax[1] = document.body.clientHeight;
	}else{
		winmax[0]=800;
		winmax[1]=600;
	}
	var box=document.getElementById("contact").style;
	//alert(((winmax[0]-450)/2)+"-"+((winmax[1]-290)/2));
	box.left = ((winmax[0]-450)/2)+"px";
	box.top= ((winmax[1]-290)/2)+"px";
}
window.onresize=centerbox;