<table cellspace=0 celladding=0 width="50%" border="1" style="margin:0">
<tr><td>
<input name="haha" style="width:100%;height:100%">
</td>
</tr>
</table>

解决方案 »

  1.   

    如果还觉得有缝隙,可把下面的margin设成负值
      

  2.   

    <!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>shawl.qiu template</title>
    <style type="text/css">
    /* <![CDATA[ */
     input{
      margin:-1px -1px -2px -1px!important;
      padding:1px!important;
      border:1px solid black!important;
     }
    /* ]]> */
    </style>
    </head>
    <body>
    <table width="600" border="1" cellpadding="0" cellspacing="0" bordercolor="#0099FF">
    <tr>
    <td width="233">&nbsp;</td>
    <td width="168">&nbsp;</td>
    <td width="191">&nbsp;</td>
    </tr>
    <tr>
    <td>&nbsp;</td>
    <td><input type="text" name="textfield" style="padding:0px 0px 0px; margin:0px 0px 0px"/></td>
    <td>&nbsp;</td>
    </tr>
    <tr>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    </tr>
    </table>
    </body>
    </html>
      

  3.   

    这样更美观一点...<!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>shawl.qiu template</title>
    <style type="text/css">
    /* <![CDATA[ */
     table{
      border-collapse:collapse!important;
     }
     input{
      margin:-1px -1px -2px -1px!important;
      padding:1px!important;
      border:1px solid black!important;
     }
    /* ]]> */
    </style>
    </head>
    <body>
    <table width="600" border="1" cellpadding="0" cellspacing="0" bordercolor="#0099FF">
    <tr>
    <td width="233">&nbsp;</td>
    <td width="168">&nbsp;</td>
    <td width="191">&nbsp;</td>
    </tr>
    <tr>
    <td>&nbsp;</td>
    <td><input type="text" name="textfield" style="padding:0px 0px 0px; margin:0px 0px 0px"/></td>
    <td>&nbsp;</td>
    </tr>
    <tr>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    </tr>
    </table>
    </body>
    </html>
      

  4.   

    哈哈,综合两位的指导,得到了满得的结果!<!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>shawl.qiu template</title>
    <style type="text/css">
    /* <![CDATA[ */
     table{
      border-collapse:collapse!important;
     }
     input{
      margin:-1px -1px 0px -1px!important;
      padding:1px!important;
      border:0px !important;
     }
    /* ]]> */
    </style>
    </head>
    <body>
    <table width="600" border="1" cellpadding="0" cellspacing="0" bordercolor="#0099FF">
    <tr>
    <td width="233">&nbsp;</td>
    <td width="168">&nbsp;</td>
    <td width="191">&nbsp;</td>
    </tr>
    <tr>
    <td>&nbsp;</td>
    <td><input type="text" name="textfield" style="width:100%;height:100%" /></td>
    <td>&nbsp;</td>
    </tr>
    <tr>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    </tr>
    </table>
    </body>
    </html>