Trim textbox values

StackOverflow question : How to trim a space at the start and end of textbox?

HTML

<a href="http://stackoverflow.com/questions/10747119/how-to-trim-a-space-at-the-start-and-end-of-textbox">How to trim a space at the start and end of textbox?</a>
<p>Search: <input type="text" name="questioncontent" onchange="return trim(this)" /></p>

JavaScript

function trim(el) {
    el.value = el.value.
    replace(/(^\s*)|(\s*$)/gi, ""). // removes leading and trailing spaces
    replace(/[ ]{2,}/gi, " "). // replaces multiple spaces with one space 
    replace(/\n +/, "\n"); // Removes spaces after newlines
    return;
}