function checkValue()
{
	var trefwoord = document.getElementById("trefwoord").value;
	if (trefwoord.length < 3)
		alert("De zoekopdracht moet uit minstens drie tekens bestaan");
	else
		if (trefwoord == "trefwoord |")
			alert("U heeft nog geen trefwoord ingevuld");
		else
			document.getElementById("frmZoeken").submit();
}

function disableEnterKey(e)
{
	 var key;

	 if(window.event)
		  key = window.event.keyCode;     //IE
	 else
		  key = e.which;     //firefox

	 if(key == 13)
		  return false;
	 else
		  return true;
}

var arVersion = navigator.appVersion.split("MSIE")
var version = parseFloat(arVersion[1])

function fixPNG(myImage) 
{
	if ((version >= 5.5) && (version < 7) && (document.body.filters)) 
	{
	   var imgID = (myImage.id) ? "id='" + myImage.id + "' " : ""
	   var imgClass = (myImage.className) ? "class='" + myImage.className + "' " : ""
	   var imgTitle = (myImage.title) ? 
					 "title='" + myImage.title  + "' " : "title='" + myImage.alt + "' "
	   var imgStyle = "display:inline-block;" + myImage.style.cssText
	   var strNewHTML = "<span " + imgID + imgClass + imgTitle
				  + " style=\"" + "width:" + myImage.width 
				  + "px; height:" + myImage.height 
				  + "px;" + imgStyle + ";"
				  + "filter:progid:DXImageTransform.Microsoft.AlphaImageLoader"
				  + "(src=\'" + myImage.src + "\', sizingMethod='scale');\"></span>"
	   myImage.outerHTML = strNewHTML	  
	}
}

function getCookie(c_name)
{
	if (document.cookie.length > 0)
	{
		c_start=document.cookie.indexOf(c_name + "=");
		if (c_start!=-1)
		{ 
			c_start = c_start + c_name.length+1 ;
			c_end=document.cookie.indexOf(";",c_start);
			if (c_end == -1) 
				c_end = document.cookie.length
			return document.cookie.substring(c_start,c_end)
		} 
	}
	return ""
}

function setCookie(c_name,value,expiredays)
{
	var exdate = new Date();
	exdate.setDate(exdate.getDate() + expiredays);
	document.cookie = c_name + "=" + escape(value) + ((expiredays==null) ? "" : ";expires=" + exdate.toGMTString()) + "; path=/"
}

function centerSite()
{					
	var viewport = document.viewport.getDimensions();
	var margintop = Math.round((viewport.height - $('containerTotal').getHeight()) / 2);

	if (margintop < 0)
		margintop = 0;
		
	$('containerTotal').style.marginTop =  margintop + "px";
	
	if (getCookie("margintop") != margintop)
		setCookie("margintop", margintop, 365);
}

window.onload = centerSite;
window.onresize = centerSite;