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Simple login verification with JavaScript

Source: Internet
Author: User
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Source code:
Copy codeThe Code is as follows:
<! Doctype html public "-// W3C // dtd html 4.01 Transitional // EN" "http://www.w3.org/TR/html4/loose.dtd">
<Html>
<Head>
<Meta http-equiv = "Content-Type" content = "text/html; charset = gb2312">
<Meta name = "Author" content = "Liu jiangbo">
<Script type = "text/javascript">
Function login (){
Var userName = document. getElementById ("userName"). value;
Var pwd = document. getElementById ("pwd"). value;
Var repwd = document. getElementById ("repwd"). value;
Var address = document. getElementById ("address"). value;
Var matchResult = true;
If (userName = "" | pwd = "" | repwd = "" | address = ""){
Alert ("Please confirm if there are any missing items! ");
MatchResult = false;
} Else if (userName. length <6 | userName. length> 20 ){
Alert ("the username length should be between 6 and 20 characters! ");
MatchResult = false;
} Else if (userName = pwd | userName = repwd ){
Alert ("the password or repeated password cannot be the same as the user name! ");
MatchResult = false;
} Else if (pwd. length <6 | pwd. length> 20 | repwd. length <6 | repwd. length> 20 ){
Alert ("the password or repeated password should be between 6 and 20 characters! ");
MatchResult = false;
} Else if (pwd! = Repwd ){
Alert ("the password is different from the repeated password. Please try again! ");
MatchResult = false;
} Else if (userName. length <6 | userName. length> 20 ){
Alert ("the username length should be between 6 and 20 characters! ");
MatchResult = false;
}

If (matchResult = true ){
Var mailreg =/^ \ w + @ \ w + (\. \ w +) + $ /;
If (! Address. match (mailreg )){
Alert ("Incorrect email format ");
MatchResult = false;
}
}


If (matchResult = true ){
If (userName. charAt (0)> = 0 & userName. charAt (0) <= 9 ){
Alert ("the user name cannot start with a number! ");
MatchResult = false;
}
}

Return matchResult;
}
</Script>
<Title> user registration and verification </title>
</Head>

<Body>
<Center>
<Form name = "loginForm" action = "http://www.ytu.edu.cn" onsubmit = "return login ()" method = "post">
<Table bgcolor = "# 6666FF" width = "300" cellspacing = "0" cellpadding = "0" border = "0" align = "left" valign = "top">
<Tr>
<Td class = "table-title" colspan = "2" align = "center" bgcolor = "# 3366FF"> User Registration </td>
</Tr>
<Tr>
<Td width = "130" height = "28" align = "left"> logon username </td>
<Td> <input id = "userName" name = "userName" type = "text" class = "input"> </td>
</Tr>
<Tr>
<Td width = "80" height = "28" align = "left"> logon password </td>
<Td> <input id = "pwd" name = "pwd" type = "password" class = "input"> </td>
</Tr>
<Tr>
<Td width = "80" height = "28" align = "left"> repeat the password </td>
<Td> <input id = "repwd" name = "repwd" type = "password" class = "input"> </td>
</Tr>
<Tr>
<Td width = "80" height = "28" align = "left"> valid email address </td>
<Td> <input id = "address" name = "address" type = "text" class = "input"> </td>
</Tr>
<Tr>

<! -- <Td width = "10" height = "28" align = "left"> </td> -->
<Td colspan = "2">
<Input type = "submit" value = "login">
<Input type = "button" value = "cancel" onClick = "reset ()"> </td>
</Tr>
</Table>
</Form>
</Center>

</Body>
</Html>

Effect implementation:

This article is an English version of an article which is originally in the Chinese language on aliyun.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to info-contact@alibabacloud.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

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