Inno-setup – Add a registry key using functions in Innosetup

[Code]
[Registry]
Root: HKLM; Subkey: "Software\company\product\Settings"; ValueType: string; ValueName: "IsServer"; ValueData : {code:InstallAsServer}

var
 Page: TInputOptionWizardPage;
 IsServer: Boolean;
procedure InitializeWizard;
 begin
 Page := CreateInputOptionPage(wpWelcome,
'Install Type','Select Install Type',
'Please select Installation type; If Server click Server else Client',
 True, False);
 
 // Add items
 Page.Add('Install as Server');
 Page.Add('Install as Client');

 // Set initial values ​​(optional)
 Page.Values[0] := True;
 Page.Values[1] := False;
 IsServer := Page.Values[0];
 end;

function InstallAsServer(emppararm: string): string; //emppararm not used just for syntax
begin
 if (IsServer=False) then 
 begin
 result:= '0';
 end
 else
 begin
 result:= '1';
 end

end;

[Registry]
Root: HKLM; Subkey: "Software\company\product\Settings"; ValueType: string; ValueName: "IsServer"; ValueData: {code:InstallAsServer}

[Code]
var
 Page: TInputOptionWizardPage;

procedure InitializeWizard;
begin
 Page := CreateInputOptionPage(wpWelcome,'Install Type','Select Install Type',
'Please select Installation type; If Server click Server else Client', True, < br /> False);

 // add items
 Page.Add('Install as Server');
 Page.Add('Install as Client');

 // set initial values ​​(optional)
 Page.Values[0] := True;
 Page .Values[1] := False;
end;

function InstallAsServer(Value: string): string;
begin
 // read the actual value directly from the Page
 if not Page.Values[0] then
 Result := '0'
 else
 Result := '1'; 
end;

How to use the value in the function to add a registry key in innosetup. I want to set the
IsServer value in the registry as the return value of InstallAsServer

[Code]
[Registry]
Root: HKLM; Subkey: "Software\company\product\Settings"; ValueType: string; ValueName: "IsServer"; ValueData: {code:InstallAsServer}

var
 Page: TInputOptionWizardPage;
 IsServer: Boolean;
procedure InitializeWizard;
 begin
 Page: = CreateInputOptionPage(wpWelcome,
'Install Type','Select Install Type',
'Please select Installation type; If Server click Server else Client',
 True, False);

 // Add items
 Page.Add('Install as Server');
 Page.Add('Install as Client');

 // Set initial values ​​(optional) 
 Page.Values[0] := True;
 Page.Values[1] := False;
 IsServer := Page.Values[0];
end;

function InstallAsServer(emppararm: string): string; //emppararm not used just for syntax
begin
 if (IsServer=False) then
 begin
 result := '0';
 end
 else
 begin
 result:= '1';
 end

end;

But even if I select server or client in the page, I always set the value to 1

This is because you are only in the wizard form Assign the value of the IsServer variable during initialization. You need to ideally read the actual value from the InstallAsServer function, so you can even delete the IsServer variable. You can simplify the code to the following:

[Registry]
Root: HKLM; Subkey: "Software\company\product\Settings"; ValueType: string; ValueName: "IsServer"; ValueData: {code:InstallAsServer}
< br />[Code]
var
 Page: TInputOptionWizardPage;

procedure InitializeWizard;
begin
 Page := CreateInputOptionPage(wpWelcome,'Install Type' ,'Select Install Type',
'Please select Installation type; If Server click Server else Client', True, 
 False);

 // add items
 Page.Add('Install as Server');
 Page.Add('Install as Client');
< br /> // set initial values ​​(optional)
 Page.Values[0] := True;
 Page.Values[1] := False;
end;
< br />function InstallAsServer(Value: string): string;
begin
 // read the actual value directly from the Page
 if not Page.Values[0] then
 Result := '0'
 else
 Result := '1'; 
end;