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I'm pretty much a beginner at Livecycle, I have the entire form that i need created & ready to go, except I need to make one field required.  I've selected user entered - required, but apparently that only makes the box red... I need some sort of error to pop up telling them that it must be filled out.  The item name is TextField11[0]

can someone help me with the java script to make an error message pop up and where to put it at for this item?