Problem Entering Created Waypoints to meet ATC requirements

[deltaV 0]

I am having trouble with "Entering Created Waypoints on the Route or Route Legs Pages" as described in the FCOM Supplementary Procedures SP.11.9. I want to enter an "along-track displacement" (for example, SEA/-10) so that I can then enter an ATC Speed/Level-By restriction adjacent to this point. However, whenever I upload something in this format (from the scratchpad) to the corresponding waypoint in the LEGS page (using the appropriate left LSK) I get CDU error "INVALID ENTRY". For example. On route towards MID VOR I want to create an ATC climb restriction; "Climb FL370, to be FL310 or above 60DME before MID". So I upload MID/-60 using the LSK next to MID on the LEGS page. The result is "INVALID ENTRY" in the scratchpad area. Not a very interesting topic, but it's frustrating the hell out of me!!! Any ideas greatfully received.

[cpawley 0]

Are you pressing the correct LSK? One option is that you are attempting to put that restriction after MID instead of before and this is confusing the systemChris

[trisager 2]

Line select MID to the scratchpad, then add /-60 and press the left LSK next to MID.

[deltaV 0]

Wow! Thanks both. Trisager's suggestion works a treat. Many thanks for the quick response. I am a happy simmer again!