// File JScript
function IsNumeric(sText){
       var ValidChars = "0123456789.";
       var IsNumber=true;
       var Char;

       for (i = 0; i < sText.length && IsNumber == true; i++) 
          { 
          Char = sText.charAt(i); 
          if (ValidChars.indexOf(Char) == -1) 
             {
             IsNumber = false;
             }
          }
       return IsNumber;
}

function AbilitaCalcolo() {
    if ( (document.getElementById("massabb").value!= "" && IsNumeric(document.getElementById("massabb").value)) && (document.getElementById("velocitabb").value != "" && IsNumeric(document.getElementById("velocitabb").value))) {
        document.getElementById("btnCalcola").disabled="";}
    else{
        document.getElementById("btnCalcola").disabled="disabled";}
}

function Calcola(){
	var massa = (document.getElementById("massabb").value / 1000);
    if (document.getElementById("UnitaMisuraVelocitabb").value == 1) {
        var velocita=document.getElementById("velocitabb").value;}
    else {
        var velocita= (document.getElementById("velocitabb").value * 0.304); 
    }
    var energiacinetica = ( 0.5 * ((massa) * (velocita*velocita)) );
    energiajoule = Math.round(energiacinetica*100)/100;
    
    if (energiajoule < 0.8){
        document.getElementById("Risultato").style.color = '#0f0'
        document.getElementById("imgUnderJoule").style.display = 'inline'
        document.getElementById("imgJouleOK").style.display = 'none'
        document.getElementById("imgJoulePerfetto").style.display = 'none'
        document.getElementById("imgOverJoule").style.display = 'none'
    }
    else if (energiajoule >= 0.8 && energiajoule <= 0.95){
        document.getElementById("Risultato").style.color = '#0f0'
        document.getElementById("imgUnderJoule").style.display = 'none'
        document.getElementById("imgJouleOK").style.display = 'inline'
        document.getElementById("imgJoulePerfetto").style.display = 'none'
        document.getElementById("imgOverJoule").style.display = 'none'
    }
    else if (energiajoule > 0.95 && energiajoule < 1){
        document.getElementById("Risultato").style.color = '#0f0'
        document.getElementById("imgUnderJoule").style.display = 'none'
        document.getElementById("imgJouleOK").style.display = 'none'
        document.getElementById("imgJoulePerfetto").style.display = 'inline'
        document.getElementById("imgOverJoule").style.display = 'none'
    }
    else {
        document.getElementById("Risultato").style.color = '#f00'
        document.getElementById("imgUnderJoule").style.display = 'none'
        document.getElementById("imgJouleOK").style.display = 'none'
        document.getElementById("imgJoulePerfetto").style.display = 'none'
        document.getElementById("imgOverJoule").style.display = 'inline'
    }
    
    document.getElementById("Risultato").value = energiajoule + ' J';
}