If you need only float or numeric value to be enter in the text box. You can use the below code.

<input name="score" id="score" type="text">

<script>

$(document).ready(function() {
    $("#score").keydown(function(event) {
        //alert(event.keyCode);
          // Allow only backspace, delete, dot, arrow key and numeric value 
        if ((event.keyCode > 95 && event.keyCode < 106) || (event.keyCode > 47 && event.keyCode < 58) || (event.keyCode == 190 || event.keyCode == 110 || event.keyCode == 8 || event.keyCode == 46 || event.keyCode == 37 || event.keyCode == 39))   {
            // let it happen, don't do anything
        }
        else {          // Ensure that it is a number and stop the keypress

                event.preventDefault(); 

        }
    });
});

</script>

NOTE :: This text box will allow only numeric or float value, if you enter any alphabetic key or special character it will not be accepted.