How do I get a status to only update when necessary in javascript? -

i'm trying create 5th edition d&d character generator app (i know, super nerdy). i'm trying have questions asked based on level character at. want update information instead of reasking of same information. example, if character ranger @ level 1, ask favored terrain , favored enemies. if have character go level 2, reask questions , ask next question related level 2. how have update information gathered level 2 , on?

i believe question answer how update experience points , not have ask same questions on , on again. if not, next question.

thanks.

here sample of code in question:

if (level >= 1){             var favterrain1 = prompt("name favorite terrain.");             var favenemy1 = prompt("name favorite enemy type or 2 humanoid races. (if select latter, please separate comma.)");             document.getelementbyid("level1").innerhtml = "<h4><b> favored terrain: </b>" + favterrain1 + "<br><b>favored enemy(enemies): </b>" + favenemy1 + "</h4>";         }         if (level >= 2) {             var lv2 = +prompt("choose fighting style: 1. archery 2. defense 3. dueling 4. two-weapon fighting");             var level2;             switch(lv2){                 case 1:                     level2 = "<b>archery</b> gain +2 bonus attack rolls make ranged weapons.";                     break;                 case 2:                     level2 = "<b>defense</b> while wearing armor, gain +1 armor class.";                     armorclass = armorclass + 1;                     break;                 case 3:                     level2 = "</b>dueling</b> when wielding melee weapon , no other weapons, gain +2 bonus damage rolls weapon.";                     break;                 case 4:                     level2 = "<b>two-weapon fighting</b> when engage in two-weapon fighting, can add ability modifier damage of second attack.";                     break;                 }             } else {                 level2= " ";             } 

it ask both level1 , level2 sets of questions if upgrade level 1 2.

by building character you're creating object in classic way: character has number of attributes build level up.

to prompt user questions necessary, can check see if player object has properties gain @ level hasownproperty function.

so use

var player = new object(); player.favoredterrain = "jungle";  if (!player.hasownproperty('favoredmount')){     //whatever code ask favored mount };  if (!player.hasownproperty('favoredterrain')){     //whatever code in here won't run because has favored terrain already! }; 

note number of frameworks make stuff much easier on large list of values e.g. angular's test see if x value populated , hide/unhide questions. alternatively, jquery make easy select , hide blocks of questions have answered. since question 'how do javascript' tried give 'pure' version