how to book skymark airlines

i try to booked tickets frm haneda to sapporo, and sapporo to nagoya {chuba} when requesting a MOBILE email address,,i couldnt get it right ..i try to key in my email address but there is a red sign of confirm your entry with the note: Please enter a MOBILE email address correctly. can you help me what am i supposed to do with this ..

Not sure, but it may be looking for a jp mobile address, such as @softbank.ne.jp, @docomo.ne.jp or @ezweb.ne.jp

Just enter your usual and same email address in both the Email and Mobile fields.

You can just leave the field blank if you have no dedicated mobile email address. However, for me it works even if I enter the same addres sas the PC one.