Get Elements By Class Name
Javascript Code
<script>
var getByClassName = function(className, parentElement) {
if (typeof parentElement == 'string'){
parentElement = document.getElementById(parentElement);
} else if (typeof parentElement != 'object' || typeof parentElement.tagName != 'string') {
parentElement = document.body;
}
var children = parentElement.getElementsByTagName('*');
var re = new RegExp('\\b' + className + '\\b');
var element, elements = [];
var i = 0;
while ( (element = children[i++]) ){
if ( ellement.className && re.test(element.className)){
elements.push(element);
}
}
return elements;
}
<script>
Markup
<div id="some_id">
<div class="first">Message 1</div>
<div class="first">Message 2</div>
</div>
Usage:
var divs1 = getByClassName('first');
var divs2 = getByClassName('first','some_id');
var divs3 = getByClassName('first',document.getElementById('some_id'));