Hi All Event rules can be usen on Forms for hiding and showing some f

To make a field readonly or required you need to make use of Advanced Form Utils.
FormAPI.setReadonly(fieldId,true);

FormAPI.setRequired(fieldId,true);

you can set a field required Conditionally by using
window.FormAPI.setRequired("fieldID",true);
window.FormAPI.setRequired("fieldID",false);

Take a look at this post forum.appian.com/.../2102

but keep in mind that using JavaScript is not recommended because that makes your form non-mobile compliant.

re: the original question - i'm not entirely sure what you're trying to accomplish but i have use cases requiring this in my project. the workaround is actually rather simple: you create two fields on the form (usually i put them next to each other), one is editable and the other is read-only (and/or disabled), and i set them both to "hide/show" in such a way that only one of them shows up at any given time. The effect on the user-end is seamless, and no javascript is required; it's fully mobile-compliant and almost no extra work on the designer.

Thanks everyone. As Eduardo explianed using javascript, the form becomes non-mobile compliant, therfore Ithink I will be going for mschmitt's solution.