i'm working on ASP.net web site , in one of my forms i added HTML control , while using that control from the code behind file i got wiered error which i can't understand .
<table style="width: 100%;" class="table-responsive">
<tr>
<td>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<input id="UserName" runat="server" type="text" class="form-control" placeholder="Username" required="required"/>
</td>
</tr>
<tr>
codeBehind file :
protected void Page_Load(object sender, EventArgs e)
{
}
public void signupData()
{
string s = UserName.text;
}
error image