what "element" are you talking about?
For subVIs you should provide some text in the VI description. That text will be shown in the context help when you move the mouse over the subVI's icon. For controls/indicators you can also provide descriptions (and captions) which will be shown in the context help window. And you can even set a label for wires…
If you add a help path you will receive a link in context help. The normal text is the description.
Please note that for linking you either need a chm or html page.
Add a description.
Help tag refers to mouse over tip strip display.
i create CHM file with HTML Help Workshop . and i Don't know how to make this program :
"when i clic to a button LabVIEW open the CHM file" .
As i stated before: you can insert such link for VI help (subVI), but not for controls.
Open the VI property dialog, switch to the "documentation" tab and browse to your chm for the Help path.