how to generate rdlc report?

This was my code and i have textbox to give username as per the query given below... but while debugging.... whole table will get display without giving the username in the textbox... but after giving the username and by clicking the submit button... report got filtered... so my report want to get generate after giving username and clicking submit....


protected void Button1_Click(object sender, EventArgs e)
{

string CS = ConfigurationManager.ConnectionStrings["ApplicationServices"].ConnectionString;
using (SqlConnection con = new SqlConnection(CS))
{

SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM logindetails WHERE([Username]='" + usertxtbox1.Text + "')", con);
DataSet ds = new DataSet();
da.Fill(ds);
ReportDataSource datasource = new ReportDataSource("DataSet1", ds.Tables[0]);
ReportViewer1.LocalReport.DataSources.Clear();
ReportViewer1.LocalReport.DataSources.Add(datasource);
ReportViewer1.LocalReport.Refresh();

}
}