Simple Moving load generation

Dear Sir,

Am a young engg. and new to staad pro. I just have to calculate an approximate moment calculation for moving loads for defined. Just for study purpose. i have created 2 beams and a set of loads defined for loading. i have generated load and defined co ordinates etc. but when i try to analyse following error occurs:

**WARNING- THIS STRUCTURE IS DISJOINTED. IGNORE IF
MASTER/SLAVE OR IF UNCONNECTED JOINTS.

*** ERROR *** ABOVE LINE CONTAINS ERRONEOUS DATA.

DATA-CHECK MODE IS ENTERED.

i have attached my model. i would be grateful if anyone explain proper method for defining and generating moving loads.

Sample_Moving1.std