Technical problems. Help please

I am still in the 1990's when it comes to technology so bear with me. The only way I can write messages is on this page or comment on someone else's comment. When I try to send message or reply to a personal message , I cannot get cursor to go to message block. I can write in subject box , not message box. Anyone have any ideas. I am writing on my IPAD.

hmm sounds like a glitch maybe?  you tap the box and nada??  wish i knew more!