how to set not show "undefined" when using Input Box through webpage

[#1]

hi

I have set a variable v_product:

I use Input box in qv,through webpage always see "undefined" in Input Box,I want to not show "undfined".

     Can anyone help me on this ?   thank you!

[#2]

If you have no input constraints on your variable, this will happen.

Go to Settings > Document Settings > Variables > Input Constraints

You can also mange these constraints while you are configuring the input box.

Go to Input Box Properties > Constraints > Input Constraints