window.showmoduledialog如何取消IE的关闭按钮

window.showmoduledialog怎么取消IE的关闭按钮?
我的代码如下，想取消弹出页面IE的关闭按钮怎么做？
<script   language= "javascript ">
function   openmodebegin()
{
if   (Form1.txtMaterial.value   ==   " ")
window.alert( "请选择货品名称 ");
else
var   returnvalue   =   window.showModalDialog( "interim.aspx ",Form1.txtMaterial.value, "dialogHeight:500px;dialogWidth:700px ", "scroll:no ");
//var   returnvalue   =   window.showModalDialog( "interim.aspx ", "abcde ", "dialogHeight:880px;dialogWidth:700px ", "scroll:no ");
Form1.txtswno.value=returnvalue;
}

</script>

------解决方案--------------------
好像不行吧，用js