If you add a custom field like html image and create a link to a control it doesnt send the variables from fields values.
Doesn’t sound as an issue to me. If you create your own link, then only the parameters of that link are sent. A link is not a submit of a form.
That´s the problem, the link doesnt send parameters!!, you create the link and specify the parameter taking the value of a field, and in the link destination (control) you can check easily if the parameter got a value with an echo and nope! the parameter is always empty, is only with the link in html image, because with a button there isnt any problem.
Paste your link code so we can look at it
Steps:
Create field type html image
Go to Edit Fields
Edit newly added field
Select any image
Click on button ‘new link’
Select target application
Select values to pass as parameter
and is all, the application is a control and the target application is also a control, without any code.