The valid inputs for field on a web site form are character strings from 5 through 25 characters in length. Test cases to perform boundary testing on this input would include valid character strings of:
0, 10, and 30 characters in length.
4, 5, 25 and 26 characters in length.
5, 6, 24 and 25 characters in length.
from 5 to 25 characters inclusively.