In serious need of assistance with files

[ingenioushax]

My program is supposed to take the balances of two entries in files, one saving and one checking, and transfer those funds as defined by the user...

-=[ New Checking & Saving Account ]=-

Name of the main holder to be on account: tommy
Checking Deposit Amount: $400
Saving Deposit Amount: $500
Press any key to continue . . .

and when I transfer the funds, it ends up like this:
-=[ Funds Transfer ]=-
-=[ Savings to Checking ]=-
Account Name: tommy
Amount to transfer: $300
New Balance in Checking: $700
New Balance in Savings: $7.78938e+012
Press any key to continue . . .

So you can see where my problem is...

here is my codes, sorry the amount of code...

I can't fit all the code in here, so I placed it on pastebin, please check it out and lemme know why the program is doing what it's doing, and how to properly overwrite the balance... The new balances end with holding onto the preceding 0's causing the new balance to be 900000 instead of 900 .

http://pastebin.com/SmTRNTFa