function addLoadEvent(func) {
	var oldonload = window.onload;

	if (typeof window.onload != 'function') {
		window.onload = func;
	}
	else {
		window.onload = function() {
			if (oldonload) {
				oldonload();
			}

		func();
		}
	}
}

function addDuplicateBackButton() {
	duplicateBackButtonLink = document.createElement('a');
	duplicateBackButtonLink.href = 'javascript:history.back();';
	duplicateBackButtonLink.appendChild(document.createTextNode('Back'));

	duplicateBackButton = document.createElement('p');
	duplicateBackButton.className = 'duplicateBackButton';
	duplicateBackButton.appendChild(duplicateBackButtonLink);

	document.getElementById('site_content').appendChild(duplicateBackButton);
}

addLoadEvent(addDuplicateBackButton);