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've got two problems here. One obvious is that you try to get a reference to the form inputs by id, but didn't give them any (you gave them a name). To fix, either change the name attribute to an id, or use the form-specific way to reference them, e.g.:

var TotalProductionTime = document.forms.frm1.TotalProductionTime

Second problem is more vicious and has to do with the scope of execution of what you put in onclick attributes. You see, your button is named "Calculate" just like your function, and in the context of the onclick attribute, its parent form is used to resolve identifiers before the global scope. So instead of calling the function named Calculate, you're trying to call the button itself. Fix that by giving them different names, referencing window.Calculate explicitly, or much better, define your event handler in JavaScript instead of using the HTML attribute:

document.forms.frm1.Calculate.onclick=Calculate