鼠标划过时整行变色

<script>function overIt(){   var the_obj = event.srcElement;   if(the_obj.tagName.toLowerCase() == "td"){       the_obj=the_obj.parentElement;       the_obj.oBgc=the_obj.currentStyle.backgroundColor;            the_obj.oFc=the_obj.currentStyle.color;       the_obj.style.backgroundColor='red';       the_obj.style.color='blue';       the_obj.style.textDecoration='underline';   }}function outIt(){   var the_obj = event.srcElement;   if(the_obj.tagName.toLowerCase() == "td"){       the_obj=the_obj.parentElement;       the_obj.style.backgroundColor=the_obj.oBgc;       the_obj.style.color=the_obj.oFc;       the_obj.style.textDecoration='';   }}</script><table border=1 width=400 onmouseover="overIt()" onmouseout="outIt()"><tr bgColor=#111111> <td>aaa</td><td>aaa</td><td>aaa</td><td>aaa</td></tr><tr bgColor=#222222> <td>aaa</td><td>aaa</td><td>aaa</td><td>aaa</td></tr><tr bgColor=#333333> <td>aaa</td><td>aaa</td><td>aaa</td><td>aaa</td></tr><tr bgColor=#444444> <td>aaa</td><td>aaa</td><td>aaa</td><td>aaa</td></tr><tr bgColor=#555555> <td>aaa</td><td>aaa</td><td>aaa</td><td>aaa</td></tr><tr bgColor=#666666> <td>aaa</td><td>aaa</td><td>aaa</td><td>aaa</td></tr><tr bgColor=#777777> <td>aaa</td><td>aaa</td><td>aaa</td><td>aaa</td></tr><tr bgColor=#888888> <td>aaa</td><td>aaa</td><td>aaa</td><td>aaa</td></tr><tr bgColor=#999999> <td>aaa</td><td>aaa</td><td>aaa</td><td>aaa</td></tr><tr bgColor=#aaaaaa> <td>aaa</td><td>aaa</td><td>aaa</td><td>aaa</td></tr><tr bgColor=#bbbbbb> <td>aaa</td><td>aaa</td><td>aaa</td><td>aaa</td></tr><tr bgColor=#cccccc> <td>aaa</td><td>aaa</td><td>aaa</td><td>aaa</td></tr><tr bgColor=#dddddd> <td>aaa</td><td>aaa</td><td>aaa</td><td>aaa</td></tr><tr bgColor=#eeeeee> <td>aaa</td><td>aaa</td><td>aaa</td><td>aaa</td></tr><tr bgColor=#ffffff> <td>aaa</td><td>aaa</td><td>aaa</td><td>aaa</td></tr></table>