function MM_preloadImages() { //v3.0
		var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
		var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
		if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
	}
	function change_but(x){
		document.getElementById('display0').style.visibility = "hidden";
		document.getElementById('display1').style.visibility = "hidden";
		document.getElementById('display2').style.visibility = "hidden";
		document.getElementById('display3').style.visibility = "hidden";
		document.getElementById('display4').style.visibility = "hidden";
		document.getElementById('display'+x).style.visibility = "visible";
		document.getElementById('but1').className = '';
		document.getElementById('but2').className = '';
		document.getElementById('but3').className = '';	
		document.getElementById('but4').className = '';
		if (x!=0) {	document.getElementById('but'+x).className = 'but_act'; }
	}