I am creating a poll in php. I have a table with an id column.

When a user submits a choice, I want the php to first query the database and check whether the table "id" has the id of the current user. 

I am pretty new at mysql, can someone help me with the query?
['https://Stackoverflow.com/questions/1992827', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/107922/']
You can do the trick with the CSS3 pseudo-class :empty

```
.someElement
{
    // your standard style
}
.someElement:empty
{
    display:none;
}

```

Sadly Internet explorer doesn't support that feauture yet. For all the other browsers it shall do just fine...
Give the empty element a different class (say `someHiddenElement`) when you are generating the content. Then add `someHiddenElement { display: none }` to your style sheet.