function IsValid(check)
{
   var ValidChars = "0123456789ABCDEFGHJKLMNPRSTUVWXY";
   var IsOK=true;
   var Char;

 
   for (i = 0; i < check.length && IsOK == true; i++) 
      { 
      Char = check.charAt(i); 
      if (ValidChars.indexOf(Char) == -1) 
         {
         IsOK = false;
         }
      }
   return IsOK;
   
   }


function makeplate() {

	var pgfx;

//	if (document.np.flag.value != '') {
//		document.images["pflag"].src = "pflags/"+document.np.flag.value+".gif";
//	}
//	if (document.np.border.value != '') {
//		newPlate = "url(plates/blank_plate"+document.np.border.value+".gif)";
//		document.getElementById('platebg').style.backgroundImage = newPlate;
//	}

	if (document.np.letter.value != '') {

		var lval = document.np.letter.value;
		var l1 = lval.charAt(0);
		var l2 = lval.charAt(1);
		if (l1 != '') {
			document.images["p1"].src = "pgfx/" + l1 + ".gif";
		}
		if (l2 != '') {
			document.images["p2"].src = "pgfx/" + l2 + ".gif";
		}

	} else {
		document.images["p1"].src = "pgfx/spacer.gif";
		document.images["p2"].src = "pgfx/spacer.gif";
	}
	if (document.np.number.value != '') {
		var num1;
		var num2;
		if (document.np.number.value.length == 2) {
			num1 = document.np.number.value.charAt(0);
			num2 = document.np.number.value.charAt(1);
			document.images["p3"].src = "pgfx/" + num1 + ".gif";
			document.images["p4"].src = "pgfx/" + num2 + ".gif";	
		} else {
			document.images["p3"].src = "pgfx/" + document.np.number.value + ".gif";
			document.images["p4"].src = "pgfx/spacer.gif";
		}
	} else {
		document.images["p3"].src = "pgfx/spacer.gif";
		document.images["p4"].src = "pgfx/spacer.gif";
	}

	if (document.np.last.value != '') {
	// can only be three chars
		var lastval = document.np.last.value.toUpperCase();

		var isgood = IsValid(lastval);

		// debugging
		//	alert('isgood = '+isgood);

		if (isgood == true) {

    		var lv1 = lastval.charAt(0);
    		var lv2 = lastval.charAt(1);
    		var lv3 = lastval.charAt(2);
    
    		if (lv1 != '') {
    			if (lv1 == 'Q' || lv1 == 'I' || lv1 == 'Z') {
    				document.images["p5"].src = "pgfx/spacer.gif";
    				alert("You cannot use Q, Z or I");
    			} else {
    				document.images["p5"].src = "pgfx/" + lv1 + ".gif";
    			}
    		} else {
    			document.images["p5"].src = "pgfx/spacer.gif";
    		}
    		if (lv2 != '') {
    			if (lv2 == 'Q' || lv2 == 'I' || lv2 == 'Z') {
    				document.images["p6"].src = "pgfx/spacer.gif";
    				alert("You cannot use Q, Z or I");
    			} else {
    				document.images["p6"].src = "pgfx/" + lv2 + ".gif";
    			}
    		} else {
    			document.images["p6"].src = "pgfx/spacer.gif";
    		}
    		if (lv3 != '') {
    			if (lv3 == 'Q' || lv3 == 'I' || lv3 == 'Z') {
    				document.images["p7"].src = "pgfx/spacer.gif";
    				alert("You cannot use Q, Z or I");
    			} else {
    				document.images["p7"].src = "pgfx/" + lv3 + ".gif";
    			}
    		} else {
    			document.images["p7"].src = "pgfx/spacer.gif";
    		}

			document.np.last.value = ""+lv1.toUpperCase()+""+lv2.toUpperCase()+""+lv3.toUpperCase()+"";

		}
		if (isgood == false) {

    		var lv1 = lastval.charAt(0);
    		var lv2 = lastval.charAt(1);
    		var lv3 = lastval.charAt(2);

			if (IsValid(lv1) == false) {
				lv1 = "";
			}
			if (IsValid(lv2) == false) {
				lv2 = "";
			}
			if (IsValid(lv3) == false) {
				lv3 = "";
			}

			document.np.last.value = ""+lv1+""+lv2+""+lv3+"";
			alert("Please enter only letters and numbers, excluding I, O, Q & Z");

		}

	}
	if (document.np.last.value.length < 1) {

		document.images["p5"].src = "pgfx/spacer.gif";
		document.images["p6"].src = "pgfx/spacer.gif";
		document.images["p7"].src = "pgfx/spacer.gif";

	}
}