windows form insert issue

Question

I connected windowsform with sql with ado and recive data in datagridview

for insert data i put textbox in my form but i tested it and put text but instead of set data into sql with sqlconnection(ado(connectionstring)) my boolean return false

private void btnsubmit_Click(object sender, EventArgs e) {
    if (ValidateInputs()) {
        bool isSuccess = repository.insert(
            txtname.Text, 
            txtfamily.Text, 
            txtemail.Text, 
            txtmobile.Text, 
            (int)txtage.Value, 
            txtadress.Text) ;
         
        if (isSuccess == true)
        {
            MessageBox.Show("Insert succeeded", "Success", MessageBoxButtons.OK,            MessageBoxIcon.Information);
            DialogResult = DialogResult.OK;
        }
        else {
            MessageBox.Show("Something went wrong","Error",MessageBoxButtons.OK);
        }

    }
}