As well as using regular expressions, I've also abusively used these functions to do the things it seems you want to do (strip html and such from a text string):
//removes all HTML tags
function striptags(stringToStrip) {
return stringToStrip.replace(/(<([^>]+)>)/ig,"");
}
//standard trim function for JavaScript--removes leading and trailing white space
function trim(stringToTrim) {
return stringToTrim.replace(/^\s+|\s+$/g,"");
}
Incredible regular expressions that have saved me a lot of time.