[jon_hill987]

Well it is worse than I thought, not only does it not work in Chrome but, if you press the button repeatedly, you can actually crash the PLC (web server). Does anyone know what is different about the way Chrome handles XMLHttpRequest posts? I can't see any difference in the data that is being sent in Firefox and Chrome and can't understand why one would crash it and the other not. Have I used the request wrong and IE and Firefox correct my error where Chrome will not? My other thought (as it can crash it) is that there might be a firmware bug in the PLC, but that does not explain how it managed to work fine in two out of the three browsers I have tested and as they don't technically support anything other than HTML (there is provision for client side scripting but the manual pretty much says that you are on your own) I need to rule out my script being wrong before I let them know I think there is a firmware issue.

I'm getting to the point where the only solution I can think of is to have it post using an html form if it detects a browser other than the ones I know to work, is that feasible? I understand browser detection can be a pain...

EDIT: So I have got around my issue with browser detection, submitting the data with an html form if it is not IE or Firefox. Interestingly Opera does exactly the same as Chrome, the submit will not work and repeated presses can crash the server. I take it no one has come across this before?