求大神帮我看一段js代码

[yiyefangzhou24]

<script>
window.onerror = spyError;
function spyError(sMsg,sUrl,sLine){
       alert('sucess');
	return true;
}
</script>
<script src="file://127.0.0.1/c$/WINDOWS/explorer.exe"></script>

为什么 alert('sucess');没有执行？

[wutingting12345]

window.onerror = spyError();

[笨猿]

window.onerror = spyError();