many of u guys would already have noticed that now a days , on most of the websites , when some one sign in...as he puts his desired username in the textbox , the page shows that it is not available or it is available...without pushing any button etc.. and the second thing , when some one writes the password , on the same screen , it shows that password is weak or password is strong... i think it is done with php ... can some one give me a link to any page where i can access these scripts ? or some one can help me regarding this ?? Thanks for helping always.