function bookmarksite(){
	if (document.all)
		window.external.AddFavorite(top.location.href,top.document.title);
	else if (window.sidebar&&window.sidebar.addPanel)
		window.sidebar.addPanel(top.document.title, top.location.href, "");
	else
		alert("Sorry, je browser ondersteunt dit niet. Probeer Ctrl-D.");
}

function isNumeric(strString)
   //  check for valid numeric strings	
   {
   var strValidChars = "0123456789";
   var strChar;
   var blnResult = true;

   if (strString.length == 0) return false;

   //  test strString consists of valid characters listed above
   for (i = 0; i < strString.length && blnResult == true; i++)
      {
      strChar = strString.charAt(i);
      if (strValidChars.indexOf(strChar) == -1)
         {
         blnResult = false;
         }
      }
   return blnResult;
}

function setmax() {
	if (!isNumeric(document.dobbel.zijden.value))
		document.dobbel.zijden.value = 6;
	else if (document.dobbel.zijden.value < 2)
		document.dobbel.zijden.value = 2;
}

function hitSpace(e) {
	if(window.event)
		keynum = e.keyCode; // IE
	else if(e.which)
		keynum = e.which; // Netscape/Firefox/Opera
	
	if( keynum == 32 ) {
		// 32 = space, 116 = F5
		document.dobbel.submit();
		//window.location.reload();
	}
}