Need Code for sim unlock for Verizon to At&t Galaxy S 4 ?

Well all I hear or see is people telling you that you need to pay a certain amount for a code to unlock your Sim to a different carrier . Well in my case I didn't by it I just used my own knowledge first before
Throwing money out The window .Sure enough I took a Verizon Samsung Galaxy S 4 nice security by the way took the Verizon S 4 went to settings mobile network changed The setting to global  then went into the APN settings  and for name : At&t put whatever you want under that At&t uses phone but I use "pta" for LTE setting . Make it easier for ya
         
   Name: AT&T
   APN: pta
  MMSC: http:// mmsc.mobile.att.net
 MMS Proxy: proxy.mobile.att.net
 MMS Port: I used 8080
  MCC: 310
  MNC: 410
 Authentication type: none
 Apn Type: default,mms,supl

Once I put that in after I put the sim card in give it a minute I actually restarted the phone went back in to check the settings again. Just make sure its on global and use those apn settings and there you have it data and phone calls worked perfectly .Might work on other phones but guaranteed fully working on a Verizon S 4 with AT&T sim without any code or money out of your pocket .