Optimizing String Shortening Algorithm?

I've written a function that "condenses" a string if it is too long.

function shortenMsg(msg,maxLen){
if (msg.length > maxLen){
var over = msg.length - maxLen, // amount that needs to be trimmed

[Code]....

Each of the methods 1-3 is the amount that that specific method can trim from the string. I'd like to be able to trim as little as possible.

For example, if the string needs 5 characters to be trimmed, and method1 can trim 8 characters, but method3 can trim 6, then method3 should be used. If none of the methods can individually trim the string enough, then I'd like the optimal combination of the methods that will get the job done.

I can't figure out what sort of code structure I need for this (besides a ton of if/else statements). Maybe an array that contains each of the methods, arranged in increasing order....?