Revise Error message when gene symbol not present

[monicabritton]

When I first go to the grid marker page, or when I backspace/delete the gene symbol in the single or double marker page (in other words, whenever there is no gene symbol in a "Primary numeric" field where it expects a gene ID), it shows this error:

Error: An error has occurred. Check your logs or contact the app author for clarification.

Is it possible to intercept this error message/revise to say something like "Please enter a gene symbol to plot." ? Or add another bold/color message to the page saying to ignore the error message?