function bodyConsistency() {
    
    var Weight = document.getElementById("WeightbodyConsistency").value;
    var periphery = document.getElementById("peripherybodyConsistency").value;    
    var Sex = document.getElementById("SexConsistency").value;    
    var Error = document.getElementById("ErrorbodyConsistency");
    var Result = document.getElementById("ResultbodyConsistency");
    var Vresult = true;
    
    // validation
    if (isNaN(Weight) || Weight <= 1 || Weight >= 300) {
        Error.innerHTML = "إدخل وزن صحيح";
        document.getElementById("WeightbodyConsistency").style.backgroundColor="Red";
        Vresult = false;
    }

    if (isNaN(periphery) || periphery <= 1 || periphery >= 600) {
        Error.innerHTML += "<br/> إدخل محيط حصر صحيح";
        document.getElementById("peripherybodyConsistency").style.backgroundColor = "Red";
        Vresult = false;
    }

    if (Vresult) {
        document.getElementById("peripherybodyConsistency").style.backgroundColor = "silver";
        document.getElementById("WeightbodyConsistency").style.backgroundColor = "silver";
        Error.innerHTML = "";
        var ganderDrefrant;
        var resultinNumber;
        var resultPercentage;        
        if (Sex == "F") {
            ganderDrefrant = -76.76;
        }
        else {
            ganderDrefrant = -98.42;
        }
            
        resultinNumber = ganderDrefrant + (4.15 * periphery * 0.3937) - (.082 * Weight * 2.205);
        resultPercentage = resultinNumber / Weight;
        resultPercentage = resultinNumber * 100;
        resultPercentage = Math.round(resultinNumber);
        if (resultPercentage > 0) {
            Result.innerHTML = " تحتاج إلى ان تخفض وزنك بنسبة " + resultPercentage + "%";
            
        }
        else if (resultPercentage < 0) {
        Result.innerHTML = " تحتاج إلى ان تذيد وزنك بنسبة " + resultPercentage + "%";
        }
        else if (resultPercentage == 0) {
        Result.innerHTML = " وزنك مثالى " +  resultPercentage  + "%";
        }
        
        
    }

}