if condition in the header template

[ohadpartuck]

hi there,
I'm trying to display(or not display a button in my site).
I have located the button in the header template

PHP Code:

<vb:if condition="$display_sos"><button id="button_grdient">S.O.S</button></vb:if> 


when I do this

PHP Code:

<vb:if condition="1"><button id="button_grdient">S.O.S</button></vb:if> 


it gets displayed so the condition is ok .

the plugin who's responsible to deliver the variable is (under global_start):

PHP Code:

$display_sos = 1;
vB_Template::preRegister('header',array('display_sos' => $display_sos)); 


i also tried this

PHP Code:

<vb:if condition="{vb:raw $display_sos}"><button id="button_grdient">S.O.S</button></vb:if> 


but got an error.

any ideas??