Error converting data type float to int.

private void btnupdate_Click(object sender, EventArgs e)
{
 
int a = dataGridView1.CurrentRow.Index;
        string x = (dataGridView1.Rows[a].Cells[1].Value).ToString();
        string y = (dataGridView1.Rows[a].Cells[3].Value).ToString();
        int z = Convert.ToInt32(x);
        double u = Convert.ToDouble(y);
obj.UPDATE_CUSTOMER(z, u);
 
}
 

CLASS LIBRARY
----------------
public IDataReader UPDATE_CUSTOMER(int customer_id, Double customer_mobile_no)
{
try
         {
             DbCommand com = db.GetStoredProcCommand(USP_Update_Customer_Data);
             db.AddInParameter(com, USP_Update_Customer_Data_PARAM_1, DbType.Int32, customer_id);
             db.AddInParameter(com, USP_Update_Customer_Data_PARAM_2, DbType.Double, customer_mobile_no);
             return db.ExecuteReader(com);
         }
         catch (Exception)
         {
             throw;
}
catch (Exception)
{
throw;
}
}
 
// UPDATE CUSTOMER DATA
private const string USP_Update_Customer_Data = "USP_Update_Customer_Data";
private const string USP_Update_Customer_Data_PARAM_1 = "customer_mobile_no";
private const string USP_Update_Customer_Data_PARAM_2 = "customer_id";
}

DATABASE TABLE WITH STORED PROCEDURE
-----------------------------------------
 
CUSTOMER_MOBILE_NO BIGINT,

ERROR
-----------
SQLEXCEPTION WAS UNHANDLED
 
Error converting data type float to int.

--------------------