function checkField(id_form)
{
	// Обрезаем лишние пробелы в начеле и в конце каждого поля, кроме капчи
	document.form1.inform.value = document.form1.inform.value.replace(/^\s+/, "").replace(/\s+$/, "");
	document.form1.email.value = document.form1.email.value.replace(/^\s+/, "").replace(/\s+$/, "");
	document.form1.name.value = document.form1.name.value.replace(/^\s+/, "").replace(/\s+$/, "");

	if(document.form1.serialNumber)
	{
		if ((String(document.form1.serialNumber.value.length) < 4 || String(document.form1.serialNumber.value.length) > 13) && id_form == "reg")
		{
			alert("Serial number should be not less than 5 characters and no more than 12.");
			document.form1.serialNumber.focus();
			return false;
		}
	}
	
	if (document.form1.inform.value == "" && id_form != "reg")
	{
		alert("Pleas enter your message.");
		document.form1.inform.focus();
		return false;
	}
	
	else if ((String(document.form1.inform.value.length) < 10 || String(document.form1.inform.value.length) > 1024) && id_form == "contact")
	{
		alert("Your message should be not less than 10 characters and no more than 1000");
		document.form1.inform.focus();
		return false;
	}
	
	else if (document.form1.inform.value.length != 0 && (String(document.form1.inform.value.length) < 10 || String(document.form1.inform.value.length) > 1024) && id_form == "reg")
	{
		alert("Your message should be not less than 10 characters and no more than 1000");
		document.form1.inform.focus();
		return false;
	}
		
    else if ((document.form1.email.value == "") || (document.form1.email.value.indexOf('@', 0) == -1))
	{
		alert("The e-mail address you entered doesn't look right.\nPlease check it and enter the correct address.");
		document.form1.email.focus();
		return false;
	}
	
	else if (document.form1.name.value == "")
	{
		alert("Pleas enter the name field.");
		document.form1.name.focus();
		return false;
	}

	else if (String(document.form1.name.value.length) < 3)
	{
		alert("The name must be at least 3 characters.");
		document.form1.name.focus();
		return false;
	}
	
	else if (document.form1.captcha.value == "")
	{
		alert("Pleas enter code from picture.");
		document.form1.captcha.focus();
		return false;
	}
	
	else
	{
  		return true;
	}
}