transparent combobox in IE

hey there guys,
i need to make a transparent combobox in IE.
I have the css code below written for changing opacity.

[CODE].transparent{
opacity:0.3;
-moz-opacity:0.3;
filter:alpha(opacity=30);
}[/CODE]
[CODE]
<select class=”transparent”>
<option>April</option>
<option>May</option>
<option>July</option>
<option>February</option>
</select>
[/CODE]

the combo box looks nice in Firefox, but IE.. ?
I think that it may need a js code to work, so I post this in js forum.
thanks in advanced ?

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