var screenres = window.screen.width;

	
function getscreenres()
{
	var scr_w = document.body.clientWidth ;

if(scr_w < 850)
	{
	document.getElementById('display').style.left =150+'px';
	}
	else if(scr_w > 1200){	document.getElementById('display').style.left=420+'px';	}
	else	
	{
	document.getElementById('display').style.left=320+'px';
	}
}
var x="d0";
function showSym(x){document.getElementById(x).style.visibility='visible';document.getElementById('d0').style.visibility='hidden';}
function hideSym(x){document.getElementById(x).style.visibility='hidden';document.getElementById('d0').style.visibility='visible';}

var theimages = new Array('exercises/images/respad.jpg','exercises/images/reshead.jpg','exercises/images/reschet.jpg','exercises/images/refeed.jpg','exercises/images/resnofed.jpg');
preloader(theimages);

function preloader(imagesarray) {
   for(var loop = 0; loop < imagesarray.length; loop++)
	{
 	var animage = new Image();
	animage.src = imagesarray[loop];
   }
}
function showthis(x)
{

for (var i=0;i<4;i++)
	{
	document.getElementById('d'+i).style.visibility='hidden';
	}
document.getElementById(x).style.visibility='visible';
}