[HELP] CSS ERROR

[LittleChild]

Hello, I dont want to waste your time, but I am really pulling my hair out over this error
My code:
HTML CODE:
<div id="header">
<h1>Welcome </h1>
</div>
CSS CODE:
#header {
height: 100px
margin:0px
text-align: left;
}
Can somebody help me ?
The CSS doesnt apply to the header

 

[Vanish]

Is the CSS file in the same folder as the HTML File?

EDIT:
margin:0px you forgot the space lol

 

[LittleChild]

oh lol and no its not its in the css folder

 

[RastaLulz]

You have to put a semicolon at the end of each property:

#header {
    height: 100px;
    margin: 0px;
    text-align: left;
}

 

[LittleChild]

Thanks so much dude, Its fixed
 
Oh yeah i did that Rooster, after i posted this. Still didnt work but Vanish told me the problem