function characterLimit(fld, e, maxlength, fld_remaining) {
		var constant
		var characters = fld.value
		prevValue = characters.length
  
	  if (e) { 
			// NN only
	    e = e 
    }
    else {
	    e = window.event // else e = winddow.event for IE
    }
    
    if (e.which) { 
			// (NN only)
	    var keycode = e.which 
    }
    else {
   	 var keycode = e.keyCode 
    } // end if
    
    if (keycode == 8) { 
			// keycode for backspace is 8, so if backspace is pressed,
      if (prevValue > 0) {
      	prevValue -= 1 
      } 
    }
    else {
			if (keycode < 65)
				// A
				prevValue = characters.length
			else prevValue += 1			
    } // end if
			
    if (prevValue <= maxlength) { 
    	constant = maxlength - prevValue 
	    fld_remaining.value = constant 
    }
    else {
			prevValue = maxlength
  	  constant = prevValue - maxlength			
    	fld_remaining.value = constant
			fld.value= fld.value.substring(0, maxlength); 
  	  fld.blur();
	    alert("U kunt geen tekst meer invoeren!\n\nUw heeft de grens van " + maxlength + " tekens overschreden.");
			fld.focus();
    }    
  } // end function 
	
	function OpenWindow(url, title) {
		var args = "width=800,height=600,resizable=no,scrollbars=yes,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no";
		var win = window.open(url, title, args);
	} // end function
	
	function OpenCategoryWindow(url, title) {
		var tmpurl = url + '&cat=' + document.getElementById("category").value;		
		OpenWindow(tmpurl, title);		
	} // end function