Javascript will not pass information into function from html -


ok new javascript. trying learn code changing text on button using external javascript file. can't javascript read buttons valueexternally, in chrome's debug tools see button value btn="". reads button object can't read properties.

<html> <head>      <title> test  </title>     <script type="text/javascript" src="gle.js"></script> </head>  <body>     <div><canvas id="gle" width="800" height="600"></canvas> </div>     <div>         <h2>enter mass , coordinates</h2>          <input id="txtbox" type="text" /><br/>         <button id="btn" onclick="change()">add</button>      </div>       </body> </html>

the gle.js

"use strict";   function change() {     var x = document.getelementbyid("btn").value;     var elem = document.getelementbyid("btn");     var txt = document.getelementbyid("txtbox");     txt.text = elem.value;     elem.value = "ok";     }

when debug x value "", nothing changes on screen. using brackets ide.

x empty because '#btn' doesn't have 'value' attribute specified. "add" string inside inner html (or text),

alert(document.getelementbyid("btn").innertext);

and can index this in event scope, it's reference of '#btn', this.innertext.

a alternative '#btn' child nodes values, cross-browser.

alert(this.childnodes[0].nodevalue);

this alert first text specified in element inner.


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