X-Cart forums - Need a IF statement for HTTPS

hi
could someone provide me with an if statement which excludes something, when the shop is called over https?

i would like to include a live chat button. everytime my shop changes from http to https, i get this terrible error message in my browser, that this site isn't secure (Because of the http:// image loading)

i don't wanna buy an extra ssl certificate for my live chat domain, so i would like to exclude the button completely once the shop uses the https server.

what if statement do i have to wrap around my code, to "remove" it?

thanks in advance