function verifyIP (IPvalue) {
errorString = "";
theName = "IPaddress";
var ipPattern = /^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/;
var ipArray = IPvalue.match(ipPattern);
if (IPvalue == "0.0.0.0")
errorString = errorString + theName + ': '+IPvalue+' ýòî ñïåöèàëüíûé IP àäðåñ è íå ìîæåò áûòü èñïîëüçîâàí.';
else if (IPvalue == "255.255.255.255")
errorString = errorString + theName + ': '+IPvalue+' ýòî ñïåöèàëüíûé IP àäðåñ è íå ìîæåò áûòü èñïîëüçîâàí.';
if (ipArray == null)
errorString = errorString + theName + ': '+IPvalue+' íå äîïóñòèìûé IP àäðåñ.';
else {
for (i = 0; i < 4; i++) {
thisSegment = ipArray[i];
if (thisSegment > 255) {
errorString = errorString + theName + ': '+IPvalue+' íå äîïóñòèìûé IP àäðåñ.';
i = 4;
}
if ((i == 0) && (thisSegment > 255)) {
errorString = errorString + theName + ': '+IPvalue+' ýòî ñïåöèàëüíûé IP àäðåñ è íå ìîæåò áûòü èñïîëüçîâàí.';
i = 4;
      }
   }
}
extensionLength = 3;
if (errorString == "")  alert ("Ââåäåííûé IP àäðåñ - êîððåêòíûé!");
else			alert (errorString);
}