Decrement on button click

by LW

HTML

<button type="button"  id="WS1dec" class="but"> - </button>  
<input type="number" id="WS1" value="2">        
 
<hr/>
<button type="button"  id="WS2dec" class="but"> - </button>  
<input type="number" id="WS2" value="1">

JavaScript

$(function() {
  $(".but").on("click",function() {
    var id=this.id;
    var fldId=id.substring(0,id.length-3);
    var inc=id.substring(id.length-3)=="inc";
    var fld = $("#"+fldId);
    var val = +fld.val();
    if (inc)val++;else val--;
    fld.val(val);
  });
});