LinkButton class is provided by Microsoft .NET framework namespace System.Web.UI.WebControls. It can be used as:
<head>
<title>LinkButton Example</title>
<script language="C#" runat="server">
void LinkButton_Click(Object sender, EventArgs e)
{
}
</script>
</head>
<body>
<form id="form1" runat="server">
<asp:LinkButton id="LinkButton1"
Text="Click Me"
Font-Names="Verdana"
Font-Size="14pt"
OnClick="LinkButton_Click"
runat="server"/>