Parse a BBCode [font=] tag

font.js

var apply = document.getElementsByClassName("postmsg");
var sigs = document.getElementsByClassName("postsignature");
var i;
for (i = 0; i < sigs.length; i++) {
  apply[apply.length] = sigs[i];
}

var fonts = [];
var texts = [];

for (i = 0; i < apply.length; i++) {
  var applyTo = apply[i];
  var thishtml = applyTo.innerHTML;
  var j;
  for (j = 0; j < thishtml.split("[font=").length-1; j++) {
    var stuff = thishtml.split("[font=")[j+1].split("]");
    fonts[j] = stuff[0];
    texts[j] = stuff[1].split("[")[0];
  }
  for (j = 0; j < fonts.length; j++) {
    fonts[j] = fonts[j].replace(/'|"/g, "");
    texts[j] = texts[j].replace(/'|"/g, "");
    thishtml = thishtml.replace(/\[font=(.+?)\](.+?)\[\/font\]/, "<span style=\"font-family: '"+fonts[j]+"'\">"+texts[j]+"</span>");
  }
  applyTo.innerHTML = thishtml;
}