function check_form()
{
	var error_message = "<? echo JS_ERROR; ?>";
	var error_found = false;
	var error_field;
	var keywords = document.advanced_search.keywords.value;
	var dfrom = document.advanced_search.dfrom.value;
	var dto = document.advanced_search.dto.value;
	var pfrom = document.advanced_search.pfrom.value;
	var pto = document.advanced_search.pto.value;
	var pfrom_float;
	var pto_float;

	if ( ((keywords == '') || (keywords.length < 1)) && ((dfrom == '') || (dfrom == '<? echo DOB_FORMAT_STRING; ?>') || (dfrom.length < 1)) && ((dto == '') || (dto == '<? echo DOB_FORMAT_STRING; ?>') || (dto.length < 1)) && ((pfrom == '') || (pfrom.length < 1)) && ((pto == '') || (pto.length < 1)) )
	{
		error_message = error_message + "* <? echo ERROR_AT_LEAST_ONE_INPUT; ?>\n";
		error_field = document.advanced_search.keywords;
		error_found = true;
	}

	if ((dfrom.length > 0) && (dfrom != '<? echo DOB_FORMAT_STRING; ?>'))
	{
		if (!IsValidDate(dfrom, '<? echo DOB_FORMAT_STRING; ?>'))
		{
			error_message = error_message + "* <? echo ERROR_INVALID_FROM_DATE; ?>\n";
			error_field = document.advanced_search.dfrom;
			error_found = true;
		}
	}

	if ((dto.length > 0) && (dto != '<? echo DOB_FORMAT_STRING; ?>'))
	{
		if (!IsValidDate(dto, '<? echo DOB_FORMAT_STRING; ?>'))
		{
			error_message = error_message + "* <? echo ERROR_INVALID_TO_DATE; ?>\n";
			error_field = document.advanced_search.dto;
			error_found = true;
		}
	}

	if ((dfrom.length > 0) && (dfrom != '<? echo DOB_FORMAT_STRING; ?>') && (IsValidDate(dfrom, '<? echo DOB_FORMAT_STRING; ?>')) && (dto.length > 0) && (dto != '<? echo DOB_FORMAT_STRING; ?>') && (IsValidDate(dto, '<? echo DOB_FORMAT_STRING; ?>')))
	{
		if (!CheckDateRange(document.advanced_search.dfrom, document.advanced_search.dto))
		{
			error_message = error_message + "* <? echo ERROR_TO_DATE_LESS_THAN_FROM_DATE; ?>\n";
			error_field = document.advanced_search.dto;
			error_found = true;
		}
	}

	if (pfrom.length > 0)
	{
		pfrom_float = parseFloat(pfrom);
		if (isNaN(pfrom_float))
		{
			error_message = error_message + "* <? echo ERROR_PRICE_FROM_MUST_BE_NUM; ?>\n";
			error_field = document.advanced_search.pfrom;
			error_found = true;
		}
	}
	else
	{
		pfrom_float = 0;
	}

	if (pto.length > 0)
	{
		pto_float = parseFloat(pto);
		if (isNaN(pto_float))
		{
			error_message = error_message + "* <? echo ERROR_PRICE_TO_MUST_BE_NUM; ?>\n";
			error_field = document.advanced_search.pto;
			error_found = true;
		}
	}
	else
	{
		pto_float = 0;
	}

	if ( (pfrom.length > 0) && (pto.length > 0) )
	{
		if ( (!isNaN(pfrom_float)) && (!isNaN(pto_float)) && (pto_float < pfrom_float) )
		{
			error_message = error_message + "* <? echo ERROR_PRICE_TO_LESS_THAN_PRICE_FROM; ?>\n";
			error_field = document.advanced_search.pto;
			error_found = true;
		}
	}

	if (error_found == true)
	{
		alert(error_message);
		error_field.focus();
		return false;
	}
	else
	{
		RemoveFormatString(document.advanced_search.dfrom, "<? echo DOB_FORMAT_STRING; ?>");
		RemoveFormatString(document.advanced_search.dto, "<? echo DOB_FORMAT_STRING; ?>");
		return true;
	}
}