的问题
<body class="spliter_color" onmouseover="if(parent.middleset.cols='0,*'){parent.middleset.cols='<%=xleft_width%>,*'}"onclick="if(parent.middleset.cols!='0,*'){parent.middleset.cols='0,*'}else{parent.middleset.cols='<%=xleft_width%>,*'};"
style="cursor: hand">
<form id="form1" runat="server">
<div>
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<table style="height: 70; width: 146px;" border="0" cellpadding="0" cellspacing="0" class="spliter_color">
<tr>
<td style="height: 5; width: 9px;" class="tree_bgcolor">
</td>
</tr>
<tr>
<td style="width: 19px; text-align: center;">
<font class="tree_bgcolor"><img id="img1" src="images/MenuImg/1.gif" alt="折叠" onmouseover="this.src='images/MenuImg/2.gif';" onmouseout ="this.src='images/MenuImg/1.gif';"width="50"/></font></td>
</tr>
<tr>
<td style="height: 2; width: 9px;" class="tree_bgcolor">
</td>
</tr>
</table>
</div>
</form>
</body>
想来回切换图片怎么试