I have several stocks from one company - how do I get them displayed as one holding?

OK, so, I buy an XYZ company at 10 dollars - it goes straight into my portfoglio, average 10 bucks.  

Tomorrow the price drops to 8, I buy another share, expecting to see one line, 2 shares, average 9... but hell no. Instead it's two separate holdings, one at 10, the other at 8. 

If I buy stocks regularly, the portfoglio will become too big to manage, what am I doing wrong?