Unable to update field prior to clicking on calculate

So I made this pet food calculator and everything is great. However, I want to change the field name of x[2] when someone selects a certain type of pet in X[1].

For instance, if someone selects Puppy, I want X[2] field name to be ‘Age in weeks’ and if they select Dog, the same fied should change to ‘Age in years’. The change needs to happen without having to click on calculate. I would like to keep calculate button intact to show the result only once clicked, but ony change the name of X[2] updon selecting the pet type. below is my code:

let type = x[1];
let age = x[2];
let weight = x[3];
let activity = x[4];

//Puppy
if(type == '1') {
if(age <11){y[1] = roundVal(0.1 * weight * 1000)} else if(age >10 && age <17){y[1] = roundVal(0.08 * weight * 1000)} else if(age >16 && age <21){y[1] = roundVal(0.07 * weight * 1000)} else if(age >20 && age <25){y[1] = roundVal(0.06 * weight * 1000)} else if(age >24 && age <37){y[1] = roundVal(0.05 * weight * 1000)} else if(age >36 && age <57){y[1] = roundVal(0.04 * weight * 1000)} else if(age >56 && age <69){y[1] = roundVal(0.03 * weight * 1000)}
else{y[1] = 'Please Fill in all Details'}
}

//Kitten
else if(type == '2') {
if(age <11){y[1] = roundVal(0.1 * weight * 1000)} else if(age >10 && age <17){y[1] = roundVal(0.08 * weight * 1000)} else if(age >16 && age <21){y[1] = roundVal(0.07 * weight * 1000)} else if(age >20 && age <25){y[1] = roundVal(0.06 * weight * 1000)} else if(age >24 && age <37){y[1] = roundVal(0.05 * weight * 1000)} else if(age >36 && age <57){y[1] = roundVal(0.04 * weight * 1000)} else if(age >56 && age <69){y[1] = roundVal(0.03 * weight * 1000)}
else{y[1] = 'Please Fill in all Details'}
}

//Dog
else if(type == '3') {
if(activity == '1'){y[1] = roundVal(0.02 * weight * 1000)}
else if(activity == '2'){y[1] = roundVal(0.03 * weight * 1000)}
else if(activity == '3'){y[1] = roundVal(0.04 * weight * 1000)}
else if(activity == '4'){y[1] = roundVal(0.05 * weight * 1000)}
else{y[1] = 'Please Fill in all Details'}
}

//Cat
else if(type == '4') {
if(activity == '1'){y[1] = roundVal(0.02 * weight * 1000)}
else if(activity == '2'){y[1] = roundVal(0.03 * weight * 1000)}
else if(activity == '3'){y[1] = roundVal(0.04 * weight * 1000)}
else if(activity == '4'){y[1] = roundVal(0.05 * weight * 1000)}
else{y[1] = 'Please Fill in all Details'}
}

else{y[1] = 'Please Fill in all Details'}

The page I need help with: [log in to see the link]

 

This site will teach you how to build a WordPress website for beginners. We will cover everything from installing WordPress to adding pages, posts, and images to your site. You will learn how to customize your site with themes and plugins, as well as how to market your site online.

Buy WordPress Transfer