TypeError: document.forms[0].showList.options is not a function
function func_select_all1() { for (i=document.forms[0].showList.options.length-1; i>=0; i--) document.forms[0].showList.options(i).selected=true; }
<html:select property="showList" multiple="true" ondblclick="func_delete();" style="width:200;height:280" >
<html:options collection="showList" property="moduleid" labelProperty="mytableStandardmodule.displayname"></html:options>
</html:select>
<input type="button" value=" 全 选 " onClick="func_select_all1();" class="SmallInput" id="button2">
</td>