Salesforce Marketing Cloud - Update Contact with AMP example

sfmc-update-sf-contact.amp

<div>

%%[

  var @Id, @contactRecord, @limitRow, @firstName, @lastName

  set @Id = RequestParameter('id')
  set @firstName = RequestParameter('firstName')
  
  if RequestParameter("submitted") == "submitted" then
  
    var @result
    set @result = UpdateSingleSalesforceObject("Contact", @Id, "FirstName", @firstName)
  
  endif
  
  set @contactRecord = RetrieveSalesforceObjects('Contact','FirstName, LastName','Id','=', @Id)
  set @limitRow = Row(@contactRecord, 1)

  set @firstName = Field(@limitRow,'FirstName')
  set @lastName = Field(@limitRow,'LastName')

]%%

<form action="%%=RequestParameter('PAGEURL')=%%" method="post">
  <input id="submitted" type="hidden" name="submitted" value="submitted" />
  <input type="text" name="firstName" value="%%=v(@firstName)=%%" />
  <input type="text" name="lastName" value="%%=v(@lastName)=%%" />
  <input type="submit" value="Submit">
</form>

</div>