sorry!

I have an Irish Broadband modem(ripwave), but, the ip is not static and I want to know how to tell my router to get ip from the modem.

Long story short the modem needs to be in the attic to get the best reception and I did get it to work for a day, then it stopped as the ip changed and the router didnt know what todo.

I've attached the screenie of the routers page where I entered the ip and gateway of the modem...but it just goes off after a day

any help greatly appreciated guy's.

First suggestion is look at your lease time - set for 1 day.
Try changing that and see if that makes a difference.

Second idea - give both the modem & router fixed ip's, ie 10.0.0.5 & 10.0.0.6 and make the modem ip the gateway ip on the machines. then allow the modem to run dhcp and that should work.
This is how I've got my work system setup and generally works well

That screen show the LAN IP config and how the router assigns IPs to the LAN computers. 10.0.0.x IP's are reserved for internal LAN computers.

You need to be looking at WAN/ADSL setup or something.