function show_search_preview(on_text, off_text)
{
	for (i = 0; i <= 99; i++)
	{
		if (document.getElementById('preview_' + i))
		{
			if (document.getElementById('preview_' + i).style.display == 'none')
			{
				document.getElementById('preview_' + i).style.display = '';
				document.getElementById('preview_link').innerHTML = off_text;
			}
			else
			{
				document.getElementById('preview_' + i).style.display = 'none';
				document.getElementById('preview_link').innerHTML = on_text;
			}
		}
		else
		{
			break;
		}
	}
}

function show_element(form_name, on_text, off_text)
{
	if (document.getElementById(form_name))
	{
		if (document.getElementById(form_name).className != '')
		{
			document.getElementById(form_name).className = '';
			document.getElementById('link' + form_name).innerHTML = off_text;
		}
		else
		{
			document.getElementById(form_name).className = 'display-none';
			document.getElementById('link' + form_name).innerHTML = on_text;
		}
	}
}

function show_category_form(category)
{
	for (i = 1; i <= 4; i++)
	{
		if (document.getElementById('category_form_' + i))
		{
			if (i == category)
			{
				document.getElementById('category_form_' + i).className = '';
				document.getElementById('category_link_' + i).className = 'category-link-active';
			}
			else
			{
				document.getElementById('category_form_' + i).className = 'display-none';
				document.getElementById('category_link_' + i).className = 'category-link';
			}
		}
	}
}

function show_article_type(form)
{
	position = form.article_type.selectedIndex;

	show_category_form(-1);

	document.getElementById('category_form_0').className = '';
	document.getElementById('category_link_0').className = 'category-link-active';

	for (i = 1; i <= 4; i++)
	{
		if (i == form.article_type[position].value)
		{
			document.getElementById('article_type_title_' + i).className = '';
			document.getElementById('article_type_form_' + i).className = '';
		}
		else
		{
			document.getElementById('article_type_title_' + i).className = 'display-none';
			document.getElementById('article_type_form_' + i).className = 'display-none';
		}
	}
}

function show_article_new_main(type)
{
	if (type >= 1 && type <= 4)
	{
		for (i = 1; i <= 4; i++)
		{
			if (i == type)
			{
				document.getElementById('article_main_' + i).className = '';
				document.getElementById('category_link_main_' + i).className = 'category-link-active';
			}
			else
			{
				document.getElementById('article_main_' + i).className = 'display-none';
				document.getElementById('category_link_main_' + i).className = 'category-link';
			}
		}
	}
}

function add_attachment()
{
	attachment_counter++;

	document.getElementById('attachment_data').innerHTML += '<p id="attachment_data_' + attachment_counter + '"><input type="file" name="attachment[]" size="50" />&nbsp;&nbsp;&nbsp;<a href="javascript:void(0)" onclick="remove_attachment(' + attachment_counter + ')">Odstranit</a></p>';
}

function remove_attachment(attachment)
{
	while(document.getElementById('attachment_data_' + attachment).hasChildNodes())
		document.getElementById('attachment_data_' + attachment).removeChild(document.getElementById('attachment_data_' + attachment).childNodes[0]);
}

function article_content_check(msg_title, msg_preview, msg_content, msg_tag)
{
	if (self.document.forms.form_article.article_title.value == '')
	{
		alert(msg_title);

		return false;
	}
	else if (self.document.forms.form_article.article_preview.value == '')
	{
		alert(msg_preview);

		return false;
	}
	else if (self.document.forms.form_article.article_content.value == '')
	{
		alert(msg_content);

		return false;
	}
	else if (self.document.forms.form_article.article_tag.value == '')
	{
		alert(msg_tag);

		return false;
	}
	else
	{
		return true;
	}
}

function discussion_content_check(msg_name, msg_iq, msg_comment)
{
	if (self.document.forms.discussion.discussion_user_name.value == '')
	{
		alert(msg_name);

		return false;
	}
	else if (self.document.forms.discussion.discussion_iq.value == '')
	{
		alert(msg_iq);

		return false;
	}
	else if (self.document.forms.discussion.discussion_comment.value == '')
	{
		alert(msg_comment);

		return false;
	}
	else
	{
		return true;
	}
}