sqldatasource access in code behind

[ADAC]

I am very familiar with Visual studio 2003 and trying to get a handle on 2005

I can set up the datasource and make it work fine when I databind it to a control like a gridview or details view. Everything is done automatically no programming.

I need to take a sqldatasource that I have already created with parameters etc. Set the parameter in the code behind, run it against the database and get the result.

in 2003 I would creat a command, run it with a datareader as use a while statement to scroll through the results. something like this.
System.Data.SqlClient.SqlDataReader dr;
this.cmdGet.Parameters["@ClientNumber"].Value = System.Int32.Parse(this.txtSearchedClient.Text);

this.cnMainConnection.Open();
dr = this.cmdGet.ExecuteReader();

while(dr.Read())
{ string myresult=dr["Phone"].ToString()}
}

I can't seem to find out how to do this with a sqldatasource. I figured that it would be like a dataadapter where I would go
dataAdapter.Selectcomand.parameters["someparameter"].value but this does not work

can anyone give me a chunk of sample code for me to work with? I can only find samples in inline asp and haven't been able to get it to work.

Thanks