Establishing the connection between database and c#

Question

Hello i a m gettng the error like 

"cann't convert from  myproject.sqlconnection to sql.Data.sqlclient.sqlconnection"

 

here  is my code 

 

protected void CalculationAddToDataBase()

{

sqlconnection conn = new sqlconnection(ConfigurationManager.ConnectionStrings["connectionstring"].ConnectionString);

conn.Open();

SqlCommand cmd = new SqlCommand("USP_PsychoetricCalculationTable",conn);

cmd.CommandType=CommandType.StoredProcedure;

}