What should a teacher do when the whole class is a disaster?

Question

I'd like to know your personal opinion, all the students are becoming really bad during an ESL classroom... sending SMS, using the PCs to do things like surfing social networks instead of the English exercises that teacher gave them, talking each other and some others laughing, eating chips.... a whole disaster... What should the teacher do if he or she has already asked them many times to behave and they just don't care?

"What should a teacher do." - ray76, Dec 29, 2010

"if he or she has already done many calls to behave well" doesn't sound very natural; you might say "if he or she has already asked them many times to behave". - kevinblash, Dec 29, 2010

Thanks a lot :) - AntMexico, Dec 30, 2010

OMG I didn't know that you've been in my class before !!!! - 00b6f46c, Dec 30, 2010