var timer = null;
var frame = 1;
var delay = 2;	// seconds
var headerImages = new Array();

function redirect(url) {
	location.href = url;
}

Event.observe(window,'load',function(){
	timer = setTimeout("rotate_headerimages()", (delay * 1000));
});


function institutionChange() {
	if ($F('institution_id') == '') {
		if ($('instName').visible()) {
			Effect.SlideUp('instName', { duration: 0.3 });
			$('institution_name').value = ''
		}
		
		$('department').disable();
		$('department').value = '';
		
		$('street').enable();
		$('city').enable();
		$('postcode').enable();
		$('country_id').enable();
		$('home_address').enable();
		
		$('street').addClassName('required');
		$('city').addClassName('required');
		$('postcode').addClassName('required');
		$('country_id').addClassName('required');
		$('country_id').addClassName('validate-selection');
	}
	else if ($F('institution_id') == 'not_listed') {
		if (!$('instName').visible()) {
			Effect.SlideDown('instName', { duration: 0.3 });
		}
		
		$('department').enable();
		$('street').enable();
		$('city').enable();
		$('postcode').enable();
		$('country_id').enable();
		$('home_address').disable();
		
		$('street').addClassName('required');
		$('city').addClassName('required');
		$('postcode').addClassName('required');
		$('country_id').addClassName('required');
		$('country_id').addClassName('validate-selection');
	}
	else {
		if ($('instName').visible()) {
			Effect.SlideUp('instName', { duration: 0.3 });
			$('institution_name').value = ''
		}
		
		$('department').enable();
		$('street').disable();
		$('city').disable();
		$('postcode').disable();
		$('country_id').disable();
		$('home_address').disable();
		
		$('street').removeClassName('required');
		$('city').removeClassName('required');
		$('postcode').removeClassName('required');
		$('country_id').removeClassName('required');
		$('country_id').removeClassName('validate-selection');
	}
}



function post_data(formID) {
	if (formID) {
		$(formID).submit();
	}
}

function rotate_headerimages() {
	if (timer != null) clearTimeout(timer);
	
	if (frame > 3) frame = 1;
	
	new Effect.Opacity('header-image-'+frame, { from: 1.0, to: 0, afterFinish: swapImage, queue: 'end'});
		
	new Effect.Opacity('header-image-'+frame, { from: 0, to: 1.0, duration: 2.0, queue: 'end'});
	
	frame++;
	
	timer = setTimeout("rotate_headerimages()", (delay * 1000));
}

function swapImage(obj) {
	var pick = Math.floor(Math.random()*(headerImages.length));
	obj.element.src = headerImages[pick];
}

function member_search() {
	var elems = $('members_searchForm').getElements();
	elems.each(function(el) { 
		if ($F(el) != '') { 
			$('members_searchForm').submit();
		}
	});  
}

function reload(formID) {
	if (formID) {
		$(formID).a.value = '';
		$(formID).submit();
	}
}

function changeTopic() {
	$('topic_form').submit();
}

function postComment() {
	if ($F('comment') != '') {
		$('comment_form').submit();
	}
}

function searchFocus(elem) {
	if (elem.value = 'Search this site') {
		elem.value = '';	
	}
}

function numerics (e) {
	var key;
	var keychar;
	
	if (window.event) {
		key = window.event.keyCode;
	}
	else if (e) {
		key = e.which;
	}
	else {
		return true;
	}
	
	keychar = String.fromCharCode(key);
	if ((key==null) || (key==0) || (key==8) || (key==9) || (key==13) || (key==27)) {
		return true;
	}
	else if (((".0123456789").indexOf(keychar) > -1)) {
		return true;
	}
	else {
		return false;
	}
}

function validate_join(form) {
	var valid = new Validation(form, { onSubmit:false, useTitles:true, immediate : true });
    var result = valid.validate();
	
	if (result) {
		return true;
	}
	
	return false;
	
}