var theWin;

function openPicture(prefix,theName,theWidth,theHeight) {
	var imgName='images/'+prefix+'/large/'+theName;
	var winName='cropic'+theName;
	var winDetails='left=20,top=20,width='+theWidth+',height='+theHeight;
	if (theWin!=null) {theWin.close();}
	theWin=window.open(imgName,'cropic',winDetails);
	theWin.focus();
}