function check_sondage(form)
{
	bChecked = false;
	iAnswer = '';
	
	for (a = 0; a < form.reponse.length; a++)
	{
		if (form.reponse[a].checked)
		{
		    iAnswer = form.reponse[a].value;
			bChecked = true;
		}
	}
	
	if (!bChecked)
	{
		alert('Veuillez choisir une reponse');
		return false;
	}
	else
	{
	    voteSondage(form.sondages_id.value, iAnswer);
	}
}

function opacity(id, opacStart, opacEnd, millisec)
{
	//speed for each frame
    var speed = Math.round(millisec / 100);
    var timer = 0;
    
    //determine the direction for the blending, if start and end are the same nothing happens
    if(opacStart > opacEnd)
    {
		for(i = opacStart; i >= opacEnd; i--)
		{
			setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        }
    }
    else if(opacStart < opacEnd)
    {
        for (i = opacStart; i <= opacEnd; i++)
        {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        }
    }
}

//change the opacity for different browsers
function changeOpac(opacity, id)
{
    var object = document.getElementById(id).style;
    object.opacity = (opacity / 100);
    object.MozOpacity = (opacity / 100);
    object.KhtmlOpacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")";
}