On *:TEXT:!ale*:#: {
if (%tab. [ $+ [ $address($nick,2) ] ] >= 100) {
.notice $nick Oya, your tab is to high, pay me before you ask more!
.halt
}
Else {
.msg $chan Ohai have fun with the ale ...
.inc %tab. [ $+ [ $address($nick,2) ] ] 10
.notice $nick You have $calc(100 - %tab. [ $+ [ $address($nick,2) ] ]) tabs remaining
}
}

If you want to change the amount of tabs he receives, just change the 10 to a number you want ( line 8 )