Try leaving the door to the crate open and putting some yummy treat inside so she will be enticed to go in. DO NOT CLOSE THE DOOR! Keep putting a little treat in it for several days until she sees that it's not a horrible place and something good happens when she goes in. When she finally isn't acting so scared, sit on the floor by the crate and call her to you and throw a treat inside. When she goes in to get it, gently pet her and tell her what a good girl she is. Just leave the door open so she doesn't feel trapped. It may take a while, but just go slowly so she doesn't see it as something scary. Put a nice blanket in there for her to lay on and give her belly rubs when she's in there. You get the idea :-) Patience is the key. Good luck.
What size dog? We have a small breed and found a neat trick to keep her contained to prevent accidents and keep her safe. We bought wire shelving that you use to build into blocks/crates. Just hook them side by side until you have a square the size you need. This won't help if your dog is big or very strong though.