Generating messages from a survey

Hi,

This code generates 4 questions with 4 radio buttons and generates a message according to a calculated result. It’s working. No errors in the console. But there’s a problem with the middle message. If you choose the first buttons for each answer expect one, the message jumps to the high risk factor, when it’s not.


function getValueForOption(optionName){
        
    var result;
    var radios = document.getElementsByName(optionName);  
    for (i = 0; i < radios.length; i++) {
         if (radios[i].checked){
              result=radios[i].value;
              return result;
         }
    }
}

window.onload = function() {

    /* Wait until the html is loaded and then add a 
       submit event */ 
    
    document.getElementById("risk-assessment").onsubmit = function(){
        var age = getValueForOption("age");
        var bmi = getValueForOption("bmi");
        var genetics = getValueForOption("genetics");
        var diet = getValueForOption("diet");
       
        var diabetesRisk = age + bmi + genetics + diet;
       
        var message;
        var messageTitle = "Your results"; 
       
       
        if( diabetesRisk <=15){
            message = "Your results show that you currently have a low risk of developing diabetes." +
            "However, it is important that you maintain a healthy lifestyle in terms of diet and exercise."; 
        } else if ( diabetesRisk <=25) {
            message = "Your results show that you currently have a medium risk of developing diabetes." + riskFactorMessage + 
            "For more information on your risk factors, and what to do about them, please visit our diabetes website at http://www.zha.org.zd.";
        } else {
        
            var riskFactorMessage = "Your main risk factors are ";  
            var riskFactors = false;
            
            if (age >=10 ) 
            {
                if (riskFactors== true) {
                    riskFactorMessage = riskFactorMessage + " and "; 
                }
                riskFactorMessage = riskFactorMessage + " your <span>AGE<span> ";
                riskFactors = true; 
            }
            if (bmi >=10 )
            {
                if (riskFactors== true) {
                    riskFactorMessage = riskFactorMessage + " and "; 
                }
                riskFactorMessage = riskFactorMessage + " your <span>BMI<span> ";
                riskFactors = true; 
            }
            if (genetics >= 10) {
                if (riskFactors== true) {
                    riskFactorMessage = riskFactorMessage + " and "; 
                }
                riskFactorMessage = riskFactorMessage + "your <span>GENETICS<span>";
                riskFactors = true; 
            }
            if (diet >= 10) {
                if (riskFactors== true) {
                    riskFactorMessage = riskFactorMessage + " and "; 
                }
                riskFactorMessage = riskFactorMessage + "your <span>DIET<span>";
                riskFactors = true; 
            }
            
            message = "Your results show that you currently have a HIGH risk of developing diabetes." + riskFactorMessage + ". We advise that you contact the Health Authority to discuss your risk factors as soon as you can." +
            "Please fill in our contact form and a member of the Health Authority Diabetes Team will be in contact with you.";
                   
        }
        
        document.getElementById("messageTitle").innerHTML = messageTitle;  
        document.getElementById("riskFactorAdvice").innerHTML= message;
        return false;


    }    

}


May be someone can comment?

Thanks in advance.