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;
	  }
	  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;
}