How to get a number value from an input field?

Question

I have some issues with calculating some stuff with JS and getting the right values out of the input fields (number). When I use this code it doesn\'t show anything. So what

Answer 1

You had some mistakes in your HTML, but here is a working JSFiddle: Fiddle

You you are trying to get elements by their ID, but you don't give them an ID you give them a Name. Also, stop using inline JavaScript calls; it is bad practice.

function Calculate() {
    var TotalProductionTime = document.getElementById("TotalProductionTime").value;
    var TotalProductionTimeInMinutes = TotalProductionTime * 60;
    var Breaks = document.getElementById("Breaks").value;
    var Malfunctions = document.getElementById("Malfunctions").value;
    var TheoreticalProductionTime = TotalProductionTimeInMinutes - Breaks - Malfunctions;

    document.getElementById("test").innerHTML = TheoreticalProductionTime;
}

    

        

            
Availability
        
        

            
Total Production Time
            

                hours
        
        

            
Breaks
            

                minutes
        
        

            
Malfunctions
            

                minutes
        
        

            
Theoretical production time: