Question
I my  husband  got me a calla lilli the other day. I noticed that the soil was dry and wanted to re pot in some better than the plastic container that it was in. I clean off the old soil and made sure that I had some fresh soil on hand as well as alittle of the old I separeted the flower as well to put  some in other pots. After I watered it I sat it by my dining room window that gets the best light and I noticed the smaller parts of the flower are starting to dag. Help

Answer
Unfortunately, you should never transplant or otherwise disturb the root system of any plant while it is in bloom.  When you do, the plants strength is put towards root structure and regrowth and taken from the bloom itself... hence your sagging blooms.

Don't overwater the Cala.  Keep it in a room where it wont get full sun, just bright light.  The blooms will probably wilt and drop early.  Cala is a bulb, so you can save the bulb by cutting back the plant after bloom and seeing if you can't get it to spike again in the future.  

Next time divide and/or transplant AFTER bloom!