$(document).ready(function(){
    $(".param").keypress(function(event){
        var inputValue = event.which;
        // allow numbers only.
        if(inputValue > 47 && inputValue < 58)  {
            event.preventDefault();
        }
    });
});



 $(document).ready(function($){


  $('body').on('keypress', function (e) {
    console.log('I have been pressed', e);
})

});



 var code = (e.keyCode ? e.keyCode : e.which);
 if(code > 47 && code < 58) { //Enter keycode
   e.preventDefault();

 }


$("form").bind("keypress", function (e) {
    if (e.keyCode == 13) {
        $("#btnSearch").attr('value');
        //add more buttons here
        return false;
    }
});


$(".text").on('keypress', function(e){

alert(e.keyCode);

  if (e.keyCode  > 47 && e.keyCode < 58) {
        return false;
    }
});



<script type="text/javascript">
    window.addEventListener('keydown', function(e) {
        if (e.keyIdentifier == 'U+000A' || e.keyIdentifier == 'Enter' || e.keyCode == 13) {
            if (e.target.nodeName == 'INPUT' && e.target.type == 'text') {
                e.preventDefault();
                return false;
            }
        }
    }, true);
</script>



<input onkeydown="Check(event);" onkeyup="Check(event);"/>
<script>
function Check(e) {
    var keyCode = (e.keyCode ? e.keyCode : e.which);
    if (keyCode > 47 && keyCode < 58) {
        e.preventDefault();
    }
}
</script>


document.querySelector("input").addEventListener("keypress", function (evt) {
    if (evt.which < 48 || evt.which > 57)
    {
        evt.preventDefault();
    }
});

document.querySelector(".sign").addEventListener("keypress", function (evt) {
    if (evt.which < 48 || evt.which > 57)
    {
        evt.preventDefault();
    }
});