var otest = document.getElementById("test"); //
var node=otest.childNodes[1];
var newNode=document.createElement("li")
newNode.innerHTML("PHP")
otest.insertBefore(newNode,node)
错误示范:newNode.innerHTML("PHP");
正确示范:newNode.innerHTML = "PHP";
还有,记得写分号,代码风格极差!!!