plz tel me how to resolve that error

my code is



<% if (gridView.PageIndex > 0)
{ %>
CommandArgument="Prev" CommandName="Page" />

<% } %>

<%=(gridView.PageIndex * 5) + 1%> <%=(gridView.PageIndex * 5) + gridView.Rows.Count%>
<% if (gridView.PageIndex != (gridView.PageCount - 1))
{ %>




<% } %>

<%--Style="vertical-align: middle;" ImageUrl="next.jpg"
CommandArgument='<%# Eval("Next")%>' OnClick="click" CommandName="Page" />--%>



<%--<%=(gridView.PageIndex * 5) + 1%> <%=(gridView.PageIndex * 5) + gridView.Rows.Count%> --%>
<% if (gridView.PageIndex != (gridView.PageCount - 1))
{ %>




<% } %>

<%--Style="vertical-align: middle;" ImageUrl="next.jpg"
CommandArgument='<%# Eval("Next")%>' OnClick="click" CommandName="Page" />--%>



and code behind is

public partial class _Default : System.Web.UI.Page
{

protected void Page_Load(object sender, EventArgs e)
{


DataSet ds = new DataSet();
SqlDataAdapter adapPaging = new SqlDataAdapter("select * from customer", "Data Source=OPWFMS-7KYGZ7SB;Initial Catalog=Mayank;User ID=sa;Password=sa");
adapPaging.Fill(ds);


gridView.DataSource = ds;
gridView.DataBind();





}

public void click1(object send, ImageClickEventArgs e)
{

GridViewPageEventArgs obj = new GridViewPageEventArgs(gridView.PageIndex - 1);

gridView.PageIndex = obj.NewPageIndex;

LinkButton exmp = new LinkButton();
exmp.Text = "exmp";
Panel1.Controls.Add(exmp);

}
public void click(object send, ImageClickEventArgs e)
{

GridViewPageEventArgs obj = new GridViewPageEventArgs(gridView.PageIndex+1);

gridView.PageIndex = obj.NewPageIndex;

}


}