selection of one item from ASP.Net ListBox

did not get

code i have

select name as theName from tab;le1 where name='"+textbox1.text+"'";
ddlValues;
ddlValues = cmd.ExecuteReader();

DropDownList1.DataSource = ddlValues;
DropDownList1.DataValueField = "theName";
DropDownList1.DataTextField = "theName";
DropDownList1.DataBind();

cmd.Connection.Close();
cmd.Connection.Dispose();