Two ComboBox Change values with seleted Value Changed

Question

Hi sir,
i have two combobox named comboTravelAgentLocation,comboTravelAgentName,when i change item from the agentloaction combobox i have to get back the agentsname from the particular area only and when i change the agent name i have to fill the values to the agent details form
here below the code please can you check and fix the error !..



public void FillTravelAgentLocation()
{
DataSet dsTAgentLoc = new DataSet();

dsTAgentLoc = Obj_Class.UserInfo("select Agent_Location from Travel_Agents where Agent_Name<>'NONE'");
DataRow dr = dsTAgentLoc.Tables[0].NewRow();
dr[0] = "--Select--";
dsTAgentLoc.Tables[0].Rows.InsertAt(dr, 0);
comboTravelAgentLocation.DataSource = dsTAgentLoc.Tables[0];
comboTravelAgentLocation.DisplayMember = "Agent_Location";
comboTravelAgentLocation.SelectedIndex = 0;
comboTravelAgentLocation.ValueMember = "Agent_Location";

comboTravelAgentLocation.DataBindings.DefaultDataSourceUpdateMode = DataSourceUpdateMode.Never;
dsTAgentLoc.Dispose();

}

private void comboTravelAgentLocation_SelectedValueChanged(object sender, EventArgs e)
{
if (comboTravelAgentLocation.SelectedIndex!=0 )
{
int Index = comboTravelAgentLocation.SelectedIndex;
string AgentLoc = comboTravelAgentLocation.SelectedValue.ToString();
FillTravelAgentName(AgentLoc);
}
}


public void FillTravelAgentName(string AgentLoc)
{
DataSet dsAgentName = new DataSet();

if (AgentLoc == "")
{

dsAgentName = Obj_Class.UserInfo("select Agent_Name from Travel_Agents where Agent_Location<>'NONE'");

DataRow drAgentName = dsAgentName.Tables[0].NewRow();
drAgentName[0] = "--Select--";
dsAgentName.Tables[0].Rows.InsertAt(drAgentName, 0);
}
else
{
dsAgentName = Obj_Class.UserInfo("select Agent_Name from Travel_Agents where Agent_Location='" + AgentLoc + "'");
DataRow drAgentName = dsAgentName.Tables[0].NewRow();
drAgentName[0] = "--Select--";
dsAgentName.Tables[0].Rows.InsertAt(drAgentName, 0);
}

comboTravelAgentName.DataSource = dsAgentName.Tables[0];
comboTravelAgentName.DisplayMember = "Agent_Name";
comboTravelAgentName.ValueMember = "Agent_Name";
comboTravelAgentName.SelectedIndex = 0;
dsAgentName.Dispose();
}


private void comboTravelAgentName_SelectedValueChanged(object sender, EventArgs e)
{
if (comboTravelAgentLocation.SelectedIndex != 0 && comboTravelAgentName.SelectedIndex != 0)
{
string AgentLocation = comboTravelAgentLocation.SelectedValue.ToString();
string AgentName = comboTravelAgentName.SelectedValue.ToString();

DataSet dsAgentDtls = new DataSet();
dsAgentDtls = Obj_Class.UserInfo("select Agent_Code,Agent_Phone,Agent_Email,Agent_Web,Agent_Address from Travel_Agents where Agent_Name='" + AgentName + "' and Agent_Location='" + AgentLocation + "'");
if (dsAgentDtls.Tables[0].Rows.Count > 0)
{
txttAgentPhone.Text = dsAgentDtls.Tables[0].Rows[0][1].ToString();
txtAgentEmail.Text = dsAgentDtls.Tables[0].Rows[0][2].ToString();
txtAgentWeb.Text = dsAgentDtls.Tables[0].Rows[0][3].ToString();
txtAgentAddress.Text = dsAgentDtls.Tables[0].Rows[0][4].ToString();
}
}
}