$.getscript("test.js");

function loadjs(file){

var head = $('head').remove('#loadscript');

$("<scri"+"pt>"+"</scr"+"ipt>").attr({src:file,type:'text/javascript',id:'load'}).appendto(head);

}

$("<scri"+"pt>"+"</scr"+"ipt>").attr({src:file,type:'text/javascript',id:'load'}).appendto($('head').remove('#loadscript'));

<script>
var SCRIPT_TIMEOUT = 20000;
var QVPL_PATH = "/QVPL1.0.0.js";

function loadHelper (jsurl) {
var oScriptEl, oTimeoutHDL, oHead;
oScriptEl = document.createElement("script");
oScriptEl.type = "text/javascript";
oScriptEl.language = "javascript";
oScriptEl.src = jsurl;
oScriptEl.onreadystatechange = doCallback;

oScriptEl.onload = function()
{
this.readyState = "complete";
doCallback();
if(typeof(lianbo) == "object"){
lianbo.init(window.QVPL);
}
};

oTimeoutHDL = window.setTimeout(doError,SCRIPT_TIMEOUT);
document.getElementsByTagName("head")[0].appendChild(oScriptEl);

function doCallback()
{
if (oScriptEl.readyState == "complete" || oScriptEl.readyState == "loaded")
{
oScriptEl.onload = oScriptEl.onreadystatechange = new Function();
window.clearTimeout(oTimeoutHDL);
}
};

function doError()
{
oScriptEl.parentNode.removeChild(oScriptEl);
};
}

loadHelper(QVPL_PATH);
</script>