Lpc2000

Hello,
my program generate no STOP bit during the writing.  Can you help me 
there
further?  Enclosed you receive the files .

...
I2DAT    = Data; 
I2CONCLR = 0x0028;    // Clear i2c und STA interrupt bit 
while(I2STAT!=0x28&&!(I2CONSET&0x08));	//wait the ACK

I2CONSET_bit.STO = 1; 
//Here STOP bit is not generated

I2CONCLR_bit.SIC = 1;
while((I2CONSET & 0x10));