Check a radio button with javascript

For some reason, I can't seem to figure this out. I have some radio buttons in my html which toggles categories: <input type="radio" name="main-categories" id="_1234" value="1234" /> // All <input type="radio" name="main-categories" id="_2345" value="2345" /> // Certain category <input type="radio" name="main-categories" id="_3456" value="3456" /> // Certain category <input type="radio" name="main-categories" id="_4567" value="4567" /> // Certain category The user can select whichever he/she wants, but when an certain event triggers, I want to set 1234 to be set checked radio button, because this is the default checked radio button. I have tried versions of this (with and without jQuery): document.getElementById('#_1234').checked = true; But it doesn't seem to update. I need it to visibly update so the user can see it. Can anybody help? EDIT: I'm just tired and overlooked the #, thanks for pointing it out, that and $.prop().