function _input_focus ()
{
    var inputs = document.getElementsByTagName("input");
    
    for(index = 0; index < inputs.length; index++)
    {
        input = inputs[index];
        
        input.onfocus = function () { this.className += " focus"; };
        input.onblur = function () { this.className=this.className.replace(new RegExp(" focus\\b"), ""); };
    }
}
// Compensation for MSIE's glaring inadequacies
if (window.attachEvent)
{
    window.attachEvent("onload", _input_focus);
}