I have a craftsman garage door opener, of which I tried to program a new remote. but it did not program. in the event I accidently errased my keypad password. How can I reprogram the keypad, i cannot get into the garage I do not have a mandoor?

Hello there,
It actually depends on what you are trying to program. And these instructions apply only to openers that do not have dip switches on them.
Remotes: push don't hold the colored learn code button all models have different colors. After pushing the button hold the remote behind your back and push it three times. On the third time the door should run.
Keyless Entry: Program the code you want into the keyless. Push the colored learn code button and then enter the code and push enter three times slowly. on the third time the door should run.
Home-Link. Hold the two outer buttons until the blinking pattern changes. Then hold the button you wish to program and point and click your remote at it. Push the colored learn code button and push the homelink button three times.
There are two models of the Wireless Keyless Entry System, the 740CB and the 940CB. The 940CB is for use only with Security+® garage door openers having an orange/red smart/learn button. The 740CB will work with all openers manufactured since 1990 that have a yellow, white, gray, or green smart/learn button. It will not work with Security+® openers.
To program the keyless entry, first locate the smart/learn button. On our chain drive models, this button is on the end farthest from the door. On our belt and screw drive models, it is on the right side as you face the door from the opener. You simply press and release the smart/learn button. You now have 30 seconds to enter your four digit PIN number into the keypad and hold the enter button for five seconds. Wait one minute and test the keyless entry by entering your four-digit PIN number and pressing enter.
With some Security+® models, you can also program your Model 940CB Wireless Keyless Entry without climbing a ladder, right from your Multi-Function Control Panel. Simply enter your pre-selected code and press and hold the enter button on your Keyless Entry. Then press and hold the light button and the pushbutton on your Multi-Function Control Panel. The garage door opener lights will flash to confirm that the Keyless Entry has been successfully programmed.
Hope this helped you solve the problem. All the best my dear friend. Elect_Comp