Limit the number of selections in a list box(or drop down)
Can you please help solve the below problem of limiting the allowed number of selections in a list box or drop down
Lets say I have a list box with 4 possible value (the values may have white space or special characters)
I would like to restrict the user the ability to select not more than 2 values at a time. Either selection of a third value should be disabled or even when selected should be ignored or when the third value is selected the first values should be automatically de-selected.