textarea validation in asp.net

Hi,

my requirement is, textarea box in asp.net shuld accept 150 alpha numerics, each line shuld accept 50 alphnumerics rest shuld be split into 2nd and 3rd line and shuld work in ie,chrome,mozilla even it shuld work when i do copy paste lines shuld splited into 3 and each line shuldcontain 50 alphanumerics.Thanks