You can use array for replacement:
var array = {"from1":"to1", "from2":"to2"}
for (var val in array)
text = text.replace(array, array[val]);
But what if you need to replace globally, ie text = text.replace(/from/g, "to");
Array is pretty big, so script will take a lot of space if I write "text = text.replace(...)" for every variable.
How can you use array in that case? "/from1/g":"to1" does not working.