K2 increase width of main page column?

Hi,
I am using the newest k2 theme and latest wordpress version.
I am trying to create my own theme and add it to the style folder.
I am having problems to increase the width of the main column.
I have increased the overall blog width to 970 px by the following:

#page {
width: 970px !important; /*Width of entire Blog*/
_width: 970px !important; /*Check in IE to get the value that matches your blog*/
border: 0px !important;
padding: 0px !important;
_padding: 0px !important;
}

However the width of the main page column still doesn’t adjust. It still wraps the words and cuts them off at the original 500 px (i think that’s the original length). I want to increase this by 200 px so I have typed the following:

#container {
float: left;
width: 700px !important;
_width: 700px !important;
}

#content

{
width: 700px !important;
_width: 700px !important;
text-align: left;
margin: 0 30px

}

Still nothing happens. the width of the main column is as before. Is there anything else I have to change??/
Would appreciate your help.
BR,
Rudi