Could you explain what exactly you try to accomplish? In general you NEVER have to get the onclick attribute from HTML elements. Also you should not specify the onclick on the element itself. Instead set the onclick dynamically using JQuery.
But as far as I understand you, you try to switch between two different onclick functions. What may be better is to implement your onclick function in such a way that it can handle both situations.
$("#google").click(function() {
if (situation) {
// ...
} else {
// ...
}
});