In edit mode, how do I change the selections weight?

I’ve got a few selected vertices I need to change the weight of in edit mode, but I can’t figure out what to do.

If you are using 2.57b, you can switch to the object data tab in the properties window, and click the plus sign to add a vertex group, then there you can apply a new weight with the slider, and hit ‘assign’ to add to the new group.

Thanks. It worked.