Untitled

<html>
	<head></head>
	<script>
		window.onload = function(){
			var botonSelect = null;

			document.onkeyup = seleccionar;
			document.onmouseup = mover;
			buttonA.onclick = reinicio;
			buttonB.onclick = reinicio;
			buttonC.onclick = reinicio;


			function seleccionar(event){
				if(event.keyCode == 65){ // Boton A pulsado
					botonSelect = document.getElementById("buttonA");

				}
			    else if(event.keyCode == 66){ // Boton B pulsado
					botonSelect = document.getElementById("buttonB");
				}
				else if(event.keyCode == 67){ // Boton C pulsado
					botonSelect = document.getElementById("buttonC");
				}
				else {
					botonSelect = null;
				}
			}

			function mover(event){
				if(botonSelect != null)
				{
					var x = event.clientX;
					var y = event.clientY;

					botonSelect.style.top = y+"px";
					botonSelect.style.left = x+"px";

				}

			}

			function reinicio(event){

					if(this.value == "a"){
						botonSelect = document.getElementById("buttonA");
						this.style.top = 0+"px";
						this.style.left = 0+"px";
						botonSelect = null;
					}
					if(this.value == "b"){
						botonSelect = document.getElementById("buttonB");
						this.style.top = 0+"px";
						this.style.left = 0+"px";
						botonSelect = null;
					}
					if(this.value == "c"){
						botonSelect = document.getElementById("buttonC");
						this.style.top = 0+"px";
						this.style.left = 0+"px";
						botonSelect = null;
					}


			}

		}
	</script>
	<style>
		input{
			position:relative;
		}
	</style>
	<body>
		<input type="button" id ="buttonA"  value = "a"/> <!-- 65-->
		<input type="button" id ="buttonB"  value = "b"/> <!-- 66-->
		<input type="button" id ="buttonC"  value = "c"/> <!-- 67-->

	</body>

</html>