iphone - problem while validation text field after -

i need validate textfield input allows 2 digits after .. eg: if enter 2.333 wont allow if can able allow 2.33 only.

for use code

- (bool)textfield:(uitextfield *)textfield shouldchangecharactersinrange:(nsrange)range replacementstring:(nsstring *)string {      nsarray *sep = [textfield.text componentsseparatedbystring:@"."];     if([sep count]==2)     {         nsstring *sepstr=[nsstring stringwithformat:@"%@",[sep objectatindex:1]];         return !([sepstr length]=2);     } } 

if use return !([sepstr length]=2) works fine wont allow enter next value.

but if remove value text field wont allow modifications. mean there no user interaction. can't able edit. can 1 please me. how can correct this. thank u in advance.

the problem code thomas clayson user still can't edit text field anymore when types example: "1234" , after inserts "." between 1 , 2, or if pastes number in textfield.

here's better solution:

- (bool)textfield:(uitextfield *)textfield shouldchangecharactersinrange:(nsrange)range replacementstring:(nsstring *)string {      nsstring *newstring = [textfield.text stringbyreplacingcharactersinrange:range withstring:string];      nsarray *sep = [newstring componentsseparatedbystring:@"."];     if([sep count]>=2)     {         nsstring *sepstr=[nsstring stringwithformat:@"%@",[sep objectatindex:1]];         return !([sepstr length]>2);     }     return yes; }