Problems with Migration Assistant

I am brand spanking new to iMac.

I want to use Migration Assistant to take files, emails etc from my old dell laptop to my new iMac. I have downloaded MA on the laptop and it is waiting to connect to my iMac, the problem is thaty I cannot get past Migration Assistant button ' Introduction ' on the iMac. Each time I hit the Continue button it goes blue then grey, and nothing happens.....

HELP!!!!!