function CheckTransformJob(id,job_id)
{
    $.ajax(
        {
            type: 'POST', data: '&job_id='+job_id, url: '/checktransformjob', success: function(data) { 
                if( data.finished )
                {
                    // stop throbber, remove grayscale & then force reload with timestamped version of im.src
                    grayscale=0
                    throbber=0
                    im.src=im.src + '?t=' + new Date().getTime();
                    return false;
                }
                else
                {
                    setTimeout( function() { CheckTransformJob(id,job_id) }, 1000,id, job_id ); 
                }
            }, 
        } )
}

function Transform(amt)
{
    id=$('#current').val()
    post_data = '&amt='+amt+'&id='+id
    // send /transform for this image, grayscale the thumbmail, add color spinning wheel overlay, and start checking for job end
    $.ajax({ type: 'POST', data: post_data, url: '/transform', success: function(data) { grayscale=1; throbber=1; DrawImg(); CheckTransformJob(id,data.job_id); return false; } })
}