Form1 frm = new Form1();
projeservices = new HProje();
projeservices.update("UPDATE ProjeEkle SET Yuklenici='" + txtyuklenicig.Text + "',IhaleBedeli='" + Convert.ToDecimal(ntxtihalebedelig.Text.Replace(",", ".")) + "',IhaleTarihi='" + Convert.ToDateTime(dtpihaletarihig.Text) + "',SozlesmeTarihi='" + Convert.ToDateTime(dtpsozlesmetarihig.Text) + "',IsinSuresi='" + ntxtisinsuresig.Text + "',TeslimTarihi='" + Convert.ToDateTime(dtptxtteslimg.Text) + "',BaslamaTarihi=,'" + Convert.ToDateTime(dtptxtbaslamag.Text) + "',BitisTarihi='" + Convert.ToDateTime(dtptxtbitisg.Text) + "' WHERE IsinAdi='" + txtisinadig.Text + "'");