onClick="window.stop() Twice?

I have a complex PHP script with iframes and I found a way to stop it:

<input type=“button” value=“Stop” onClick=“window.stop()”>

However, I have to click the button twice. I was wondering if anyone knew or could guide me towards a trick in JavaScript to allow such a function?

for IE, you need to use document.execCommand(“Stop”). You may still experience problems with Safari, so I suggest you test.

Actually, I’m running everything through Mozilla Prism. Is what I’m trying to accomplish even possible?