function load_script(xyUrl, callback){ var head = document.getElementsByTagName('head')[0]; var script = document.createElement('script'); script.type = 'text/javascript'; script.src = xyUrl; //借鉴了jQuery的script跨域方法 script.onload = script.onreadystatechange = function(){ if((!this.readyState || this.readyState === "loaded" || this.readyState === "complete")){ callback && callback(); // Handle memory leak in IE script.onload = script.onreadystatechange = null; if ( head && script.parentNode ) { head.removeChild( script ); } } }; // Use insertBefore instead of appendChild to circumvent an IE6 bug. head.insertBefore( script, head.firstChild ); }