function backtotop() {
    var x1 = x2 = x3 = 0;
    var y1 = y2 = y3 = 0;

    if (document.documentElement) {
        x1 = document.documentElement.scrollLeft || 0;
        y1 = document.documentElement.scrollTop || 0;
    }

    if (document.body) {
        x2 = document.body.scrollLeft || 0;
        y2 = document.body.scrollTop || 0;
    }

    x3 = window.scrollX || 0;
    y3 = window.scrollY || 0;

    var x = Math.max(x1, Math.max(x2, x3));
    var y = Math.max(y1, Math.max(y2, y3));

    window.scrollTo(Math.floor(x / 2), Math.floor(y / 2));

    if (x > 0 || y > 0) {
        window.setTimeout("backtotop()", 25);
    }
}

function MultiSelector( list_target, max ){

	// Where to write the list
	this.list_target = list_target;
	// How many elements?
	this.count = 0;
	// How many elements?
	this.id = 0;
	// Is there a maximum?
	if( max ){
		this.max = max;
	} else {
		this.max = -1;
	};
	
	/**
	 * Add a new file input element
	 */
	this.addElement = function( element ){

		// Make sure it's a file input element
		if( element.tagName == 'INPUT' && element.type == 'file' ){

			// Element name -- what number am I?
			element.name = 'figure_' + this.id++;

			// Add reference to this object
			element.multi_selector = this;

			// What to do when a file is selected
			element.onchange = function(){

				// New file input
				var new_element = document.createElement( 'input' );
				new_element.type = 'file';

				// Add new element
				this.parentNode.insertBefore( new_element, this );

				// Apply 'update' to element
				this.multi_selector.addElement( new_element );

				// Update list
				this.multi_selector.addListRow( this );

				// Hide this: we can't use display:none because Safari doesn't like it
				this.style.position = 'absolute';
				this.style.left = '-1000px';

			};
			// If we've reached maximum number, disable input element
			if( this.max != -1 && this.count >= this.max ){
				element.disabled = true;
			};

			// File element counter
			this.count++;
			// Most recent element
			this.current_element = element;
			
		} else {
			// This can only be applied to file input elements!
			alert( 'Error: not a file input element' );
		};

	};

	/**
	 * Add a new row to the list of files
	 */
	this.addListRow = function( element ){

		// Row div
		var new_row = document.createElement( 'div' );

		// Delete button
		var new_row_button = document.createElement( 'input' );
		new_row_button.type = 'button';
		new_row_button.value = 'Verwijder';

		// References
		new_row.element = element;

		// Delete function
		new_row_button.onclick= function(){

			// Remove element from form
			this.parentNode.element.parentNode.removeChild( this.parentNode.element );

			// Remove this row from the list
			this.parentNode.parentNode.removeChild( this.parentNode );

			// Decrement counter
			this.parentNode.element.multi_selector.count--;

			// Re-enable input element (if it's disabled)
			this.parentNode.element.multi_selector.current_element.disabled = false;

			// Appease Safari
			//    without it Safari wants to reload the browser window
			//    which nixes your already queued uploads
			return false;
		};

		// Set row value
		new_row.innerHTML = "<p class=\"normal\" style=\"display:inline;margin-right:10px;\">" + element.value + "</p>";

		// Add button
		new_row.appendChild( new_row_button );

		// Add it to the list
		this.list_target.appendChild( new_row );
		
	};

};

function openmonthpicker(companyid, prodid) {
	URL = 'monthpicker.php?companyid=' + companyid + '&prodid=' + prodid;
	width = 175;
	height = 125;
  var_left = Math.round((screen.width - width) / 2);
	var_top = Math.round((screen.height - height) / 2);
	day = new Date();
	id = day.getTime();
	eval("page" + id + " = window.open(URL, '" + id + "', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width=' + width + ',height=' + height + ',left = ' + var_left + ',top = ' + var_top + '');");
//	window.open(', 'Maand selecteren', 'left=400,top=400,width=175,height=125,menubar=no,status=no').focus();
}

function verify(){
	if(confirm('Weet u zeker dat u alle geselecteerde bedrijven een mail wilt sturen met hun gebruikersnaam en wachtwoord?')) {
		document.mailusers.submit();
	}
}

function CheckCheckAll(fmobj) {
	var checked = document.mailusers.allcompanies.checked;
  for (var i=0;i<fmobj.elements.length;i++) {
    var e = fmobj.elements[i];
    if ((e.name != 'allcompanies') && (e.type=='checkbox')) {
			e.checked = checked;
    }
  }
}

function SelectOptionByValue(selectid, value) {
	selectbox = document.getElementById(selectid);
	len = selectbox.length;
	i = 0;
	for (i = 0; i < len; i++) {
	 if (selectbox[i].value == value)
		 selectbox.selectedIndex = i;
	}
}