Why is this not working? It is supposed to work this way: if the checkbox is checked, it should take the content of a variable txt and write it to the input with id of show.
function myFunction() {
if (document.getElementById('myRadio').checked) {
var txt = "Done";
document.getElementById("show").innerHTML = 'txt';
}
}<p>If the radio checkbox is checked the text from the variable text is written into input line with the ID of show</p>
<input type="checkbox" onclick="myFunction()" id="myRadio">
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<br>
<input type="text" class="form-control" id="show">You need to set the value property of the input element, not the innerHTML:
function myFunction() {
if (document.getElementById('myRadio').checked){
var txt = "Done";
document.getElementById("show").value = txt;
} else {
document.getElementById("show").value = '';
}
}<p>If the radio checkbox is checked the text from the variable text is written into input line with the ID of show</p>
<input type="checkbox" onclick="myFunction()" id="myRadio">
<br>
<br>
<input type="text" class="form-control" id="show">