This is the code.
error occured at "parameters.Add".
Please help me by solving this problem

pp = new System.Data.OleDb.OleDbConnection("Provider=Microsoft.JET.OLEDB.4.0;Data Source=c:\\Form.mdb");
pp.Open();
ppc = new System.Data.OleDb.OleDbCommand("insert into Registration(Name,Id)values(@a,@b)",pp);
ppc.Parameters.Add("@a",name.Text);
ppc.Parameters.Add("@b",id.Text);
ppc.ExecuteNonQuery();
pp.Close();

Thank you

try it after putting 

ppc.Parameters.Add("@a",name.Text.toString());

in place of 
 

ppc.Parameters.Add("@a",name.Text);

Jeevesh