How recieve string into controller

Hi everybody!

I work with Keil C251 uVision2.
in my programm i want to recieve string into controller. i have an array of characters incom[20], which i use as a buffer for recieving string. i recieve current byte into variable bufIn and then replace it into my array:

 1.  	strcat(incom, bufIn);

or

 2.     incom[i] = bufIn;
	i++;

in 2 cases before (1) & (2) i test with my routine Print(unsigned char) and can see that every next byte is recieved into bufIn variable, and after (1) & (2) i can see that byte is stored into the next byte of incom[] array.
But after recieving the whole string while testing array:

for(i = 0; i < 20; i++)
     Print(incom[i]);

i can see the empty string with only the last recieved byte on the last place, for example: " a".
If anybody can help me to recieve the whole string?
And else. Why i can't create any array of characters more than 20 symbols?
Thaks.
Gennady.