function URLEncode(plaintext )
{
 // The Javascript escape and unescape functions do not correspond
 // with what browsers actually do...
 var SAFECHARS = "0123456789" +     // Numeric
     "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + // Alphabetic
     "abcdefghijklmnopqrstuvwxyz" +
     "-_.!~*'()";     // RFC2396 Mark characters
 var HEX = "0123456789ABCDEF";

 var encoded = "";
 for (var i = 0; i < plaintext.length; i++ ) {
  var ch = plaintext.charAt(i);
     if (ch == " ") {
      encoded += "+";    // x-www-urlencoded, rather than %20
  } else if (SAFECHARS.indexOf(ch) != -1) {
      encoded += ch;
  } else {
      var charCode = ch.charCodeAt(0);
   if (charCode > 255) {
       alert( "Unicode Character '"
                        + ch
                        + "' cannot be encoded using standard URL encoding.\n" +
              "(URL encoding only supports 8-bit characters.)\n" +
        "A space (+) will be substituted." );
    //encoded += "+";
     encoded += charCode;
   } else {
    encoded += "%";
    encoded += HEX.charAt((charCode >> 4) & 0xF);
    encoded += HEX.charAt(charCode & 0xF);
   }
  }
 } // for

 return encoded;
};