function replaceSubstring(inputString, fromString, toString) {   
   var temp = inputString;
   if (fromString == "") {
      return inputString;
   }
   if (toString.indexOf(fromString) == -1) { 
      while (temp.indexOf(fromString) != -1) {
         var toTheLeft = temp.substring(0, temp.indexOf(fromString));
         var toTheRight = temp.substring(temp.indexOf(fromString)+fromString.length, temp.length);
         temp = toTheLeft + toString + toTheRight;
      }
   } else { 
      var midStrings = new Array("~", "`", "_", "^", "#");
      var midStringLen = 1;
      var midString = "";
     
      while (midString == "") {
         for (var i=0; i < midStrings.length; i++) {
            var tempMidString = "";
            for (var j=0; j < midStringLen; j++) { tempMidString += midStrings[i]; }
            if (fromString.indexOf(tempMidString) == -1) {
               midString = tempMidString;
               i = midStrings.length + 1;
            }
         }
      } 
      while (temp.indexOf(fromString) != -1) {
         var toTheLeft = temp.substring(0, temp.indexOf(fromString));
         var toTheRight = temp.substring(temp.indexOf(fromString)+fromString.length, temp.length);
         temp = toTheLeft + midString + toTheRight;
      }
      // Next, replace the "inbetween" string with the "toString"
      while (temp.indexOf(midString) != -1) {
         var toTheLeft = temp.substring(0, temp.indexOf(midString));
         var toTheRight = temp.substring(temp.indexOf(midString)+midString.length, temp.length);
         temp = toTheLeft + toString + toTheRight;
      }
   } 
   return temp; // Send the updated string back to the user
}