var selectedDate = document.getElementById("dateexecution").value;
var items = selectedDate.split('/');
var seldate = new Date(items[2],items[1]-1,items[0]);

var todaysDate = new Date();

if(todaysDate > selectedDate){
 alert("Too old");
 document.getElementById("dateexecution").style.border="2px solid red";
 document.getElementById("dateexecutionerror").style.display="inline";
}