How to prevent a semicolon from being entered into html text input, but allowing a colon?

I want to allow input such as 1:10, but not 1;10. However, : and ; both correspond to keyCode 186, so using keyCode to prevent the ; key from inputting into my input field does not work. I also researched into using charCodes, but charCodes don't have the ; or : values. Finally, I looked at ascii tables. They have semicolon and colon values. Is there any way for me to possibly use ascii tables to prevent the ; key from inputting into my textbox, but the : key to be allowed? Or is there another approach that will let me do this? I also thought about detecting two key inputs in a row, so that I could detect a shift key input, but that seems like a dirty solution.

 $("input.form-1").bind({
    keydown: function(e) {
        if(e.which ===186) { //trying to disallow semicolons, which also disallows colons
            return false;
        }
    }
});