Page 1/3 of the Javascript form verification control code list

Keywords: JS verification form Daquan, use js to control form submission, JavaScript to submit form:
Directory:
1: JS string length limit, determination character length, JS restriction input, restriction not input, textarea length limit
2.: JS judges Chinese characters, determines whether Chinese characters are needed, and can only input Chinese Characters
3: JS determines whether the input is in English. Only English can be entered.
4: javascript can only enter numbers, determine numbers, verify numbers, detect numbers, determine whether they are numbers, and only enter numbers
5: Only English characters and numbers can be entered
6: JS email verification, JS judgment email, mailbox/mailbox format Verification
7: JS character filtering, blocking keywords
8: JS password verification and password Determination
2.1: JS is not empty, empty, or not an object. The judgment is empty. The judgment is not empty.
2.2: compare whether the values of two form items are the same
2.3: The form can only contain numbers and "_",
2.4: Number/length limit entered for Form Items
2.5: Chinese/English/number/email address legality judgment
2.6: Restrict characters that cannot be entered for Form Items
2.7 form User Control
2.8: Common verification functions for form text fields

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 name = A onsubmit = "return test ()">
<Textarea name = "B" Cols = "40" Wrap = "virtual" rows = "6"> </textarea>
<Input type = "Submit" name = "Submit" value = "check">
</Form>

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

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

<Input onkeydown = "onlyeng ();">

4. Only numbers are allowed.
<Script language = JavaScript>
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 onkeydown = "onlynum ();">

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

6. Verify the fuel tank format
<Script language = JavaScript 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 type = text onblur = isemail (this. Value)>

7. blocking keywords (here, shielding ***** and *****)

8. Whether the two passwords are the same
<Form method = post action = "">
<Input type = "password" id = "input1">
<Input type = "password" id = "input2">
<Input type = "button" value = "test" onclick = "check ()">
</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" ondragstart = "Return false" onselectstart = "Return false"
Add to Body

II

2.1 Form items cannot be blank

<Script language = "JavaScript">
<! --
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 language = "JavaScript">
<! --
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 language = "JavaScript">
<! --
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