你传的知识个字符串呀
function show(T_id,bkColor,Tborder,color){
 T_id=document.getElementById(T_id);  //这样就好了
 this.T_id = T_id
 T_id.style.backgroundColor="'"+bkColor+"'";
 T_id.style.border="1px solid '"+Tborder+"'";
 T_id.style.color="'"+color+"'";
 }

解决方案 »

  1.   

    <HTML>
    <HEAD>
    <TITLE> New Document </TITLE>
    <META NAME="Generator" CONTENT="EditPlus">
    <META NAME="Author" CONTENT="">
    <META NAME="Keywords" CONTENT="">
    <META NAME="Description" CONTENT="">
    </HEAD>
     
    <BODY>
    <SCRIPT LANGUAGE="JavaScript">
    <!--
    function show(T_id,bkColor,Tborder,color){
     var t_id = document.getElementById(T_id);
     t_id.style.backgroundColor =bkColor;
     t_id.style.border="1px solid "+Tborder;
     t_id.style.color=color;
     }
    //-->
    </SCRIPT><table width="75%" border="0">
      <tr onMouseOver="return show('id15','#eaf3fa','#78b1e2','#205f96');"> 
    <td><div align="right" class="style6"><strong>&Otilde;&aelig;&Ecirc;&micro;&ETH;&Otilde;&Atilde;&ucirc; <span class="style4">*</span> 
    </strong></div></td>
    <td><input type="text" name="usertruename" size="15"></td>
    <td class="td" id="id15" style="background-color: #ffffff;border:1px solid #FFffff;">&Ccedil;&euml;&Icirc;&ntilde;±&Oslash;&Igrave;&icirc;&ETH;&acute;&Otilde;&aelig;&Ecirc;&micro;&micro;&Auml;&ETH;&Otilde;&Atilde;&ucirc;</td>
      </tr>
    </table></BODY>
    </HTML>
      

  2.   

    <SCRIPT LANGUAGE="JavaScript">
    <!--
    function show(T_id,bkColor,Tborder,color){
    obj = document.getElementById(T_id);
    obj.style.backgroundColor=bkColor;
    obj.style.border="1px solid "+Tborder+"";
    obj.style.color=color;
    }
    //-->
    </SCRIPT>
    <table width="75%" border="0">
      <tr onClick="show('id15','#eaf3fa','#78b1e2','#205f96');"> 
    <td><div align="right" class="style6"><strong>真实姓名 <span class="style4">*</span> 
    </strong></div></td>
    <td><input type="text" name="usertruename" size="15"></td>
    <td class="td" id="id15" style="background-color: #ffffff;border:1px solid #FFffff;">请务必填写真实的姓名</td>
      </tr>
    </table>