javascript - disable textfield until select option from select list -

i have list of option inside select list, have textfield contain option value when selected. make textfield disable default , when i'm selecting 1 of options - textfield enable. can direct me simiar example?

thanks

here example using plain javascript jsfiddle:

html:

<select id='myselect'>     <option value='none'>none</option>     <option value='1'>1</option>     <option value='2'>2</option>     <option value='3'>3</option> </select> <input type='text' value='' name='mytext' id='mytext' disabled /> <button value='add' id='addbtn' name='addbtn'>add</button> 

we started disabled input textfield.

var myselect = document.getelementbyid('myselect');  function createoption() {     var currenttext = document.getelementbyid('mytext').value;     var objoption = document.createelement("option");     objoption.text = currenttext;     objoption.value = currenttext;      //myselect.add(objoption);     myselect.options.add(objoption); }  document.getelementbyid('addbtn').onclick = createoption;  myselect.onchange = function() {     var mytextfield = document.getelementbyid('mytext');     if (myselect.value == 'none'){         mytextfield.value = '';         mytextfield.disabled = true;     }else {         mytextfield.value = myselect.value;         mytextfield.disabled = false;     } } 

using example on previous post add onchange state select tag when option selected set textfield's value selected, , set textfield's disable false. thus, enable textfield when option selected. additionally, added option called 'none' when user selects none it'll diable textfield.