To fire onclick event automatically on page load using Javascript

if(navigator.appName !="Microsoft Internet Explorer")

{
HTMLElement.prototype.click = function()

{
var evt = this.ownerDocument.createEvent('MouseEvents');
evt.initMouseEvent('click', true, true, this.ownerDocument.defaultView, 1, 0, 0, 0, 0, false, false, false, false, 0, null);
this.dispatchEvent(evt);
}

}