Once Click Label Control,Focus move to other control without use TabIndex property in ASP.NET
<asp:Label ID="lblName" runat="server" AssociatedControlID="txtName" Text="Enter Name"></asp:Label>
<asp:TextBox ID="txtName" runat="server"></asp:TextBox>
In the above code,lblName is associated to the TextBox "txtName". When executed and the focus will be returned to the TextBox if we click on the label text "Enter your Name".
In HTML
<label for="txtName" id="Label1">Enter your Name</label>
<input name="txtName" type="text" id="txtName" />