Question

How can I disable an input-field with jQuery using GM if the url contains text?

I tried

$(document).ready( function() {
    if($("url:contains('text')")){
        $(".input[id=field-owner]:disabled");
    }
    else {
        $(".input[id=field-owner]:enabled");
    }
});

I don’t know what I did wrong. And I also don’t know whether url:code is a regular expression to use.

Update

Hi again,
thanks for your time putting in this. I guess it’s easier to ask/answer how to call an alert when the url contains e.g. “newthread”.

So, we have got a url(e.g.): http://forum.jswelt.de/newthread.php?do=newthread&f=1 ,
and an input-field with id=”subject” and a label for “subject”.
If the url contains “newthread” the input-and label-element should be hidden.
Following code works, but not for me. The console says nothing and won’t alert though.

var url = window.location.href 
url = "http://forum.jswelt.de/newthread.php?do=newthread&f=1";
    var pos = url.search(/newthread/); 
    if(pos >= 0)
        alert("tadaa");
    else
        alert("mist");

🙁

Thank you to all helping me.

Edit inserts the final solution

if (location.href.indexOf("text") != -1) {
$('#fieldname').attr("disabled", true); 

Answer 1

Throw away that snippet. Should be like

(function($){
  $(document).ready(function(){
     var url = window.location.href;

     if(/text/g.test(url)){
        $('#field-owner').attr('disabled', 'disabled');
     }
     else{
        $('#field-owner').removeAttr('disabled');
     }
  });
})(jQuery);

edit

“$ not defined” means you either aren’t loading the jQuery library or $ gets overwritten.
I put the whole snippet into a self-executing anonymous function which will fix the last issue at least.