It takes two clicks for a button to update my datagrid

Hi,

I have a datagrid, consisting of both template and bound columns, that's manually populated at runtime.  I'm trying to add a button that'll sort and display the data in the grid.  The sort is done by re-submitting a query to SQL Server with "ORDER BY" appended.  

Afterwards, the "sort-by" column is stored in Session so that whenever Page_Load occurs, the data will be sorted correctly.

My problem is, it appears to take two clicks of the button to sort the data grid.  In other words, the Button1_Click function fails to sort the grid (so Page_Load has to do it).

I tried stepping through the code, and whenever I press the button, it first runs Page_Load, and only THEN Button1_Click (so that Session["sort-by"] is set correctly only the next time Page_Load is run).

Please help! (Code below)

private void Page_Load(object sender, System.EventArgs e)
{                  
  if (!IsPostBack)
  {
    GetSource2();
    BindGrid();
  }
  else
  {
    if(Session["sort-by"] != null)
    sqlSelectCommand1.CommandText += " ORDER BY " + Session["sort-by"];
    GetSource2();
    BindGrid();
   }
}

void BindGrid()
{
  // Set the data source and bind to the Data Grid control.
  DataGrid1.DataSource = equipmentDataSet;
  DataGrid1.DataBind();
}

void GetSource2()
{
  EquipmentSqlConn.Open();
  sqlDataAdapter1.Fill(equipmentDataSet);
  EquipmentSqlConn.Close();
}

private void Button1_Click(object sender, System.EventArgs e)
{
  Session["sort-by"] = " IP";
  sqlSelectCommand1.CommandText += " ORDER BY IP";
  GetSource2();
  BindGrid();
}