One button firing another buttons click event

I'm only familiar with ASP.net and C# buttons, but using C# you could wire two different buttons to the same click event handler. You could also do it client side by triggering the primary buttons click event with your secondary button. Here's a VERY simple example:

HTML

<input type="button" id="primaryButton" onclick="ExistingLogic()" />
<input type="button" 
       id="secondaryButton" 
       onclick="document.getElementById('primaryButton').click()" />

<input type="button" id="primaryButton" onclick="ExistingLogic()" />
<input type="button" id="secondaryButton"/>

$('#secondaryButton').click(function(){
    $("#primaryButton").click();
})