Format number in an HTML5 input tag

Question

This is my input

Is it possible to only allow users to enter

Answer 1

function inputLimiter(e,allow) {
    var AllowableCharacters = '';

    if (allow == 'custom'){AllowableCharacters=' 1234567890.';}


    var k = document.all?parseInt(e.keyCode): parseInt(e.which);
    if (k!=13 && k!=8 && k!=0){
        if ((e.ctrlKey==false) && (e.altKey==false)) {
        return (AllowableCharacters.indexOf(String.fromCharCode(k))!=-1);
        } else {
        return true;
        }
    } else {
        return true;
    }
    
    }

In Javascript. But this was as far as I got, will just leave this here for awhile, need to handle other stuffs.