ending a procedure

[Maikeru1990]

im at college doing this project using delphi for a server and coding and using html and databases to creating a system that you can input details to store and create appointments though i want it to show a message when a field is empty and i click submit button

because when i click it the message appears but the procedure carrys on and the field gets stored empty still after i click the message off

any help would be gratefully appreciated
i feel like its something so simple yet i cant figure it out

if this helps this is a part of my code to help you.

//***Fathers Application Form Submit***

  quFathersApplicationFormSubmit.Close;
  quFathersApplicationFormSubmit.Parameters.ParamByName('pmFForename').Value := slParamsList.Values['AFFForename'];
    if (slParamsList.Values['AFFForename'] = '') then ShowMessage ('Fathers forename has no value') and quFathersApplicationFormSubmit.Close;
  quFathersApplicationFormSubmit.Parameters.ParamByName('pmFSurname').Value  := slParamsList.Values['AFFSurname'];
    if (slParamsList.Values['AFFSurname'] = '') then ShowMessage ('Fathers surname has no value');
  quFathersApplicationFormSubmit.Parameters.ParamByName('pmFDoB').Value      := slParamsList.Values['AFFDDOB'] + '/' + slParamsList.Values['AFFMDOB'] + '/' + slParamsList.Values['AFFYDOB'];
  quFathersApplicationFormSubmit.Parameters.ParamByName('pmFAddress').Value  := slParamsList.Values['AFFAddress'];
    if (slParamsList.Values['AFFAddress'] = '') then ShowMessage ('Fathers Address has no value');
  quFathersApplicationFormSubmit.Parameters.ParamByName('pmFPostcode').Value := slParamsList.Values['AFFPostcode'];
    if (slParamsList.Values['AFFPostcode'] = '') then ShowMessage ('Fathers Postcode has no value');
  quFathersApplicationFormSubmit.Parameters.ParamByName('pmFStatus').Value   := slParamsList.Values['AFFStatus'];
    if (slParamsList.Values['AFFStatus'] = '') then ShowMessage ('Fathers status has no value');
  quFathersApplicationFormSubmit.Parameters.ParamByName('pmFJobTitle').Value   := slParamsList.Values['AFFJob'];
    if (slParamsList.Values['AFFJob'] = '') then ShowMessage ('Fathers job has no value');
  quFathersApplicationFormSubmit.Parameters.ParamByName('pmFWorkAddress').Value   := slParamsList.Values['AFFWorkAddress'];
    if (slParamsList.Values['AFFWorkAddress'] = '') then ShowMessage ('Fathers job address has no value');
  quFathersApplicationFormSubmit.execSql;

[WingedPanther]

I would do elseif to chain that, with the actual "good" logic in the else statement.