function filevermaak() {
	day = new Date();
	id = day.getTime();
	eval("page" + id + " = window.open('viral/viral.php', '" + id + "', 'toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=0,width=800,height=800,left = 100,top = 100');");
}


function berekenReistijdWerkdagen(minuuten, dagen)  {
	
	if(minuuten > 500) {
		minuuten = 500;
		document.getElementById('minuuten').value = 500;
	}
	if(dagen > 7) {
		dagen=7;
		document.getElementById('dagen').value = 7;
	}	

	if(is_numeric(minuuten) && is_numeric(dagen)) {
	

		var tot_minuuten = minuuten * dagen;
		
		var uren = tot_minuuten / 60;
		var werkdagdeel = uren / 8;
		var onderweg = werkdagdeel * 4;
		  
		document.getElementById('textbox_resultaat').innerHTML = "Je bent <span>" + to2DecWithComma(onderweg) + "</span> werkdagen per maand onderweg.";
	}
}


function to2DecWithComma(num)
{
	num="" + Math.floor(num*100.0 + 0.5)/100.0;

	var i=num.indexOf(".");

	if ( i<0 ) num+=",00";
	else {
		num=num.substring(0,i) + "," + num.substring(i + 1);
		var nDec=(num.length - i) - 1;
		if ( nDec==0 ) num+="00";
		else if ( nDec==1 ) num+="0";
		else if ( nDec>2 ) num=num.substring(0,i + 3);
	}

	return num;
}

function is_numeric( mixed_var ) {

	//alert(mixed_var);
	if(mixed_var == "") { return false; }
	
    // http://kevin.vanzonneveld.net
    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   improved by: David
    // *     example 1: is_numeric(186.31);
    // *     returns 1: true
    // *     example 2: is_numeric('Kevin van Zonneveld');
    // *     returns 2: false
    // *     example 3: is_numeric('+186.31e2');
    // *     returns 3: true
 	
    return !isNaN( mixed_var );
}