This code truncates a string of text by counting the maximum number of characters, and replacing the rest with 3 dots.

String.prototype.reduce = function(l, p) {
         var words = this.split(" ");
         var wordCount = words.length;
         var output = [];
         var ol, cWord, w;
         for (w = 0; w < wordCount; ++w) {
                 cWord = words[w];
                 cwl = cWord.length;
                 if ((ol + cwl) <= l) {
                         output.push(cWord);
                         ol += cwl + 1;
                 } else {
                         break;
                 }
         }
         return output.join(" ") + p;
 };
 //USAGE
 myText = "Bah bah, black sheep, have you any wool?";
 cutRhyme = myText.reduce(10, "...");
 trace("the cut string is : " + cutRhyme);
 //outputs
 //Bah bah black sheep...

from FlashGuru

-- ArthurClemens - 17 May 2003