function checkForm(f)
{

if(f.company.value == "")
{
alert("The field [Company, address] is necessary entry");
document.forms[0].company.focus()
return false;
}

if(f.tel1.value == "")
{
alert("The field [Contact telefon/fax] is necessary entry");
document.forms[0].tel1.focus()
return false;
}

if(f.user.value == "")
{
alert("The field [Executor name's] is necessary entry");
document.forms[0].user.focus()
return false;
}

if(f.message.value == "")
{
alert("The field [Prospective contents of the equipment] is necessary entry");
document.forms[0].message.focus()
return false;
}

return true;
}