private void RegisterJavaScript()
{
const string scriptKey = "grid-filter-script";
const string script = @"
$('div.grid-filter header').click(function () {
$('i.toggle-filter', this).toggleClass('fa-chevron-down fa-chevron-up');
var $hf = $('input', this).first();
if($hf.val() != 'true') {
$hf.val('true');
} else {
$hf.val('false');
}
$(this).siblings('div').slideToggle();
});
";
ScriptManager.RegisterStartupScript( this, this.GetType(), scriptKey, script, true );
}