//Import the MessageUI Framework into your project and  
//#import the header file into the “.h” file of your controller  
//where you want to open the In-App SMS sheet. 
-(IBAction) sendInAppSMS:(id) sender 
{ 
    MFMessageComposeViewController *controller = 
        [[[MFMessageComposeViewController alloc] init] autorelease]; 
    if([MFMessageComposeViewController canSendText]) 
    { 
        controller.body = @"Hello from Mugunth"; 
        controller.recipients = [NSArray arrayWithObjects: 
                @"12345678", @"87654321", nil]; 
        controller.messageComposeDelegate = self; 
        [self presentModalViewController:controller animated:YES]; 
    } 
}