vb.net - Filling values in DataGridView -

i want display result of select query in datagridview clause in query. condition specified in label's value. i.e

select *  hospital_details  location_name= '" & label6.text & "'" 

following code

public sub fill()      try         createconnection()         da = new sqldataadapter         dim c string         c = label6.text         comm.commandtext = "select * hospital_details location_name= '" & label6.text & "'"         da.selectcommand = comm         da.fill(ds, "hospital_details")         datagridview2.datasource = ds.tables(0)         datagridview2.datamember = "hospital_details"         datagridview2.readonly = true      catch ex exception          msgbox("error: " & ex.source & ": " & ex.message, msgboxstyle.okonly, "connection error !!")      end try  end sub 

but showing error : nullexception

you can load data sql server , follow link http://mssqlguid.blogspot.in/2013/07/how-to-load-data-into-datagridview-from.html