script可以在页面全部加载前执行吗？
这段script代码总要等整个页面加载完毕才能执行，网页里有个气象预报的框架，加载很慢，总要等气象预报加载完毕才可以执行这段script代码。怎样让这段script代码提前加载：
<script type="text/javascript">window.onload = function() { var c = document.getElementById('controller').getElementsByTagName('td'); var ar = ['http://www.baidu.com/s', 'http:m.baidu.com/m']; for(var i = 0; i < c.length; i ++) { c[i].onclick = function() { c[0].style.backgroundColor = '#FFF'; c[1].style.backgroundColor = '#FFF'; c[this.cellIndex].style.backgroundColor = '#0FF'; document.getElementById('searcher').action = ar[this.cellIndex]; } }}</script><table> <tr align="center" id="controller"> <td style="background-color:#0FF"><a href="javascript:">网页</a></td> <td><a href="javascript:">音乐</a></td> </tr> <tr> <td colspan="2"> <form action="http://www.baidu.com/s" target="_blank" id="searcher"> <input name="word" type="text" value="" /> <input type="submit" value="百度一下" /> </form></td> </tr></table>天气预报：<iframe src="http://m.weather.com.cn/m/pn1/weather.htm " width="235" height="16" marginwidth="0" marginheight="0" hspace="0" vspace="0" frameborder="0" scrolling="no"></iframe><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>无标题文档</title><script type="text/javascript">//这样试试function changeSearcher(obj) { var c = document.getElementById('controller').getElementsByTagName('td'); var ar = ['http://www.baidu.com/s', 'http://mp3.baidu.com/m']; for(var i = 0; i < c.length; i ++) c[i].style.backgroundColor = '#FFF'; c[obj.cellIndex].style.backgroundColor = '#0FF'; document.getElementById('searcher').action = ar[obj.cellIndex];}</script></head><body><table> <tr align="center" id="controller"> <td style="background-color:#0FF" onclick="changeSearcher(this);"><a href="javascript:void(0);">网页</a></td> <td onclick="changeSearcher(this);"><a href="javascript:void(0);">音乐</a></td> </tr> <tr> <td colspan="2"> <form action="http://www.baidu.com/s" target="_blank" id="searcher"> <input name="word" type="text" value="" /> <input type="submit" value="百度一下" /> </form></td> </tr></table>天气预报：<iframe src="http://m.weather.com.cn/m/pn1/weather.htm " width="235" height="16" marginwidth="0" marginheight="0" hspace="0" vspace="0" frameborder="0" scrolling="no"></iframe></body></html>