function PopWindow(uri,winheight,winwidth) { 
    if (document.all){
        var xMax = screen.width, yMax = screen.height;
    }
    else{
        if (document.layers){
            var xMax = window.outerWidth, yMax = window.outerHeight;
        }
        else{
            var xMax = 800, yMax=600;
	}
    }

    if (xMax<=800){
	    var xAdd=0,ySub=0;	
	    var xOffset = 0, yOffset = (yMax-ySub)/6;		
    }
    else{
	    var xAdd=0,ySub=0;
	    var xOffset = 0, yOffset = (yMax-ySub)/4;		
    }

    mywin=window.open(uri,'Picture','height='+winheight+',width='+winwidth+',screenX='+xOffset+',screenY='+yOffset+',top='+yOffset+',left='+xOffset+',location=0,menubar=0,statusbar=0,locationbar=0,scrollbars=1,resizable=0');
    mywin.focus();
    return mywin;
}