Some Times it would give Error, "Error In Connecting To Instaphone Server." which means there is some Load on Instaphone servers due to which you are unable to connect. Try again after a few moments...

 And if you get "Error in Sending SMS. Please try again later..." which means there was some kind of connection problem, so try sending sms again after few minutes... 

Click Here For Instaphone Java Applet SMS Version