Simple JS Form Verification

JS verification form Overview
1. length limit
<SCRIPT>
Function Test ()
{
If (document. A. B. value. length> 50)
{
Alert ("cannot exceed 50 characters! ");
Document. A. B. Focus ();
Return false;
}
}
</SCRIPT>
<Form test () ">
<Textarea Cols = "40" Wrap = "virtual" rows = "6"> </textarea>
<Input value = "check">
</Form>

2. Only Chinese characters are allowed
<Input/oblog/value. Replace (/[^ \ u4e00-\ u9fa5]/g, '')">

3. "English only
<SCRIPT>
Function onlyeng ()
{
If (! (Event. keycode> = 65 & event. keycode <= 90 ))
Event. returnvalue = false;
}
</SCRIPT>

<Input>

4. Only numbers are allowed.
<SCRIPT>
Function onlynum ()
{
If (! (Event. keycode> = 48 & event. keycode <= 57) | (event. keycode> = 96 & event. keycode <= 105 )))
// Consider the numeric keys on the keypad
Event. returnvalue = false;
}
</SCRIPT>

<Input>

5. Only English characters and numbers are allowed.
<Input/oblog/value. replace (/[\ W]/g, "'') "onbeforepaste =" clipboardData. setdata ('text', clipboardData. getdata ('text '). replace (/[^ \ D]/g, '')">

6. Verify the fuel tank format
<SCRIPT runat = Server>
Function isemail (stremail ){
If (stremail. search (/^ \ W + (-\ W +) | (\. \ W +) * \ @ [A-Za-z0-9] + ((\. |-) [A-Za-z0-9] + )*\. [A-Za-z0-9] + $ /)! =-1)
Return true;
Else
Alert ("oh ");
}
</SCRIPT>
<Input>
7. Shielding keywords (here, shielding ***** and ****)
<SCRIPT>
Function Test (){
If (. b. value. indexof ("***") = 0) | (. b. value. indexof ("***") = 0 )){
Alert (":)");
A. B. Focus ();
Return false ;}
}
</SCRIPT>
<Form test () ">
<Input> <input value = "check">
</Form>

8. Whether the two passwords are the same
<Form method = post action = "">
<Input>
<Input>
<Input value = "test">
</Form>
<SCRIPT>
Function check ()
{
With (document. All ){
If (input1.value! = Input2.value)
{
Alert ("false ")
Input1.value = "";
Input2.value = "";
}
Else document. Forms [0]. Submit ();
}
}
</SCRIPT>
Enough.
Blocking right-click is cool
Oncontextmenu = "Return false"
Add to Body

II

2.1 Form items cannot be blank

<SCRIPT>
<! --
Function checkform ()
{
If (document. Form. Name. value. Length = 0 ){
Alert ("enter your name! ");
Document. Form. Name. Focus ();
Return false;
}
Return true;
}
-->
</SCRIPT>

2.2 compare whether the values of the two form items are the same

<SCRIPT>
<! --
Function checkform ()
If (document. Form. pwd. value! = Document. Form. pwd_again.value ){
Alert ("the password you entered twice is different! Enter again .");
Document. adduser. pwd. Focus ();
Return false;
}
Return true;
}
-->
</SCRIPT>

2.3 form items can only be numbers and "_", used for phone/Bank Account Verification, and can be extended to domain name registration.

<SCRIPT>
<! --
Function isnumber (string)
{
VaR letters = "1234567890-"; // you can add input values by yourself.
VaR I;
VaR C;
If (string. charat (0) = '-')
Return false;
If (string. charat (string. Length-1) = '-')
Return false;
For (I = 0; I <string. length; I ++)
{
C = string. charat (I );
If (letters. indexof (c) <0)
Return false;
}
Return true;
}
Function checkform ()
{
If (! Isnumber (document. Form. Tel. Value )){
Alert ("your phone number is invalid! ");
Document. Form. Tel. Focus ();
Return false;
}
Return true;
}
-->
</SCRIPT>

2.4 form entry input value/length limit

<SCRIPT>
<! --
Function checkform ()
{
If (document. Form. Count. value> 100 | document. Form. Count. value <1)
{
Alert ("the input value cannot be less than zero or greater than 100! ");
Document. Form. Count. Focus ();
Return false;
}
If (document. Form. Message. value. Length <10)
{
Alert ("the input text is less than 10! ");
Document. Form. Message. Focus ();
Return false;
}
Return true;
}
// -->
</SCRIPT>

2.5 Determination of validity of Chinese/English/numbers/email addresses

<SCRIPT>
<! --

Function isenglish (name) // english value detection
{
If (name. Length = 0)
Return false;
For (I = 0; I <name. length; I ++ ){
If (name. charcodeat (I)> 128)
Return false;
}
Return true;
}

Function ischinese (name) // Chinese value detection
{
If (name. Length = 0)
Return false;
For (I = 0; I <name. length; I ++ ){
If (name. charcodeat (I)> 128)
Return true;
}
Return false;
}

Function Ismail (name) // E-mail value detection
{
If (! Isenglish (name ))
Return false;
I = Name. indexof ("");
J = Name dot lastindexof ("");
If (I =-1)
Return false;
If (I! = J)
Return false;
If (I = Name dot length)
Return false;
Return true;
}

Function isnumber (name) // value detection
{
If (name. Length = 0)
Return false;
For (I = 0; I <name. length; I ++ ){
If (name. charat (I) <"0" | Name. charat (I)> "9 ")
Return false;
}
Return true;
}

Function checkform ()
{
If (! Ismail (Form. Email. Value )){
Alert ("your email is invalid! ");
Form. Email. Focus ();
Return false;
}
If (! Isenglish (Form. Name. Value )){
Alert ("the English name is invalid! ");
Form. Name. Focus ();
Return false;
}
If (! Ischinese (Form. cnname. Value )){
Alert ("invalid Chinese name! ");
Form. cnname. Focus ();
Return false;
}
If (! Isnumber (Form. publiczipcode. Value )){
Alert ("the zip code is invalid! ");
Form. publiczipcode. Focus ();
Return false;
}
Return true;
}
// -->
</SCRIPT>

2.6 restrict characters that cannot be entered for Form Items

<SCRIPT>
<! --

Function contain (STR, charset) // string contains the test function
{
VaR I;
For (I = 0; I <charset. length; I ++)
If (Str. indexof (charset. charat (I)> = 0)
Return true;
Return false;
}

Function checkform ()
{
If (contain (document. form. name. value, "% \ (\)> <") | (contain (document. form. message. value, "% \ (\)> <")))
{
Alert ("illegal characters entered ");
Document. Form. Name. Focus ();
Return false;
}
Return true;
}
// -->
</SCRIPT>

1. check whether a string is composed of digits.
---------------------------------------
<SCRIPT> <! --
Function checknum (STR) {return Str. Match (/\ D/) = NULL}
Alert (checknum ("1232142141 "))
Alert (checknum ("123214214a1 "))
// --> </SCRIPT>

2. How to determine whether it is a character
---------------------------------------
If (/[^ \ x00-\ xFF]/g. test (s) Alert ("containing Chinese characters ");
Else alert ("All characters ");

3. How to determine whether Chinese characters are contained
---------------------------------------
If (escape (STR). indexof ("% u ")! =-1) Alert ("containing Chinese characters ");