how to fetch html id value in code behind c# page.

Question

 

My code as follows

<div class="dropdownparent" style="float: left; width: 250px; height: 25px;">

<select id="ms" runat="server" multiple="mutiple"

style="float: left; width: 250px;" class="ms" title="Select Project">

</select>

protected void ImgbtnExcelClick(object sender, ImageClickEventArgs e)

{

string projectid = this.ms.Value;

}

But when i run the above code shows error as follows

Cannot create an object of type 'System.Boolean' from its string representation 'multiple' for the 'Multiple' property.

The above error comes because this below line

<select id="ms" runat="server" multiple="mutiple"

style="float: left; width: 250px;" class="ms" title="Select Project">

</select>

The error comes because of multiple = "mutiple"

please help me . how to solve my error