An example of IP address verification

I usually feel that the Windows IP input box is very easy to use. It must be nice if it can be implemented on a webpage. The core code is as follows:
<Script language = "javascript">
Function outStr (){
If (document. all. ip1.value> 0 & document. all. ip2.value> 0 & document. all. ip3.value> 0 & document. all. ip4.value> 0 ){
Alert ("The IP address you entered is:" + document. all. ip1.value + ". "+ document. all. ip2.value + ". "+ document. all. ip3.value + ". "+ document. all. ip4.value );
} // End if
} // End
Function moveRight (obj ){
Id = parseInt (obj. name. substr (2, 1 ))
If (id <4 ){
Eval ("document. all. ip" + (id + 1) + ". focus ()");
} Else {
OutStr ();
} // End if
}
Function moveLeft (obj ){
Id = parseInt (obj. name. substr (2, 1 ))
If (id> 1 ){
Eval ("document. all. ip" + (id-1) + ". focus ()");
} // End if
} // End if
Function Keypress (obj ){
Var objInput = obj;
Cod = window. event. keyCode;

If (cod = 46 & (obj. value). length> 0) {// if you press "." and have a character, move it to the right once.
Window. event. keyCode = 0;
MoveRight (obj );
} Else if (obj. value). length = 2 & (cod> = 48) & (cod <= 57) {// if the number key has two digits
If (cod <58 ){//
Obj. value = obj. value * 10 + cod-48;
} // End if
Window. event. keyCode = 0;
MoveRight (obj );
} Else {// determines if the input is a number.
If (! (Cod> = 48) & (cod <= 57) | (cod = 13) | (cod = 37) | (cod = 39 ))){
Window. event. keyCode = 0;
} // End if
} // End if
} // End function keydown
Function getCaretPos (obj ){
Var currentRange = document. selection. createRange ();
Var workRange = currentRange. duplicate ();
Obj. select ();
Var allRange = document. selection. createRange ();
Var len = 0;
While (workRange. compareEndPoints ("StartToStart", allRange)> 0 ){