Function for capitalising the first letters in a sentence

firstlettercapitalise.js

function FirstLetterCapitalise(message) {
  if((typeof message === "undefined") || (typeof message !== "string")) {
    return "You have to pass in a string.";
  } else {
    var buffer, blength, newbuf, newstr, nblength, char, result;
    buffer = message.split(" ");
    blength = buffer.length;
    result = "";
    for(var i = 0; i < blength; i++) {
      char = buffer[i].charAt(0);
      if((char.match(/^[A-Za-z]+$/) === null) || (char.match(/^[A-Z]+$/))) {
        result += buffer[i];
      } else if(char.match(/^[a-z]+$/)) {
        newstr = buffer[i];
        newbuf = newstr.split("");
        newbuf[0] = newbuf[0].toUpperCase();
        nblength = newbuf.length
        newstr = "";
        for(var j = 0; j < nblength; j++) {
          newstr += newbuf[j];
        }
        result += newstr;
      }
      if(i !== (blength - 1)) {
        result += " ";
      }
    }
  }
  return result; 
}