JavaScript Discussion Boards

please help me to write ...

A) Write the code for the login.html document (Client side) which gives the following interface. When the user clicks on the button you must check if the user enters data or not, if the fields are empty you must present an alert message and do not send the data to the server side. If the user entered login and password, then your program must call the validate.php document.

B) Write the code of the server side validate.php page such that.
1) The validate.php checks if the login is valid or not. A valid login must
start with a letter and followed by any one or more of the characters:_, 0-9, A-Z, a-z
For instance, a1, ab_1, and Z_2d are valid logins while _a1, b*, and
c23_@2 are invalid logins. But, there are no restrictions on the password; the user
can use any character in the keyboard. (hint. You must use the regular expression
in php).

2) The validate.php page reads the login and passwords from a database
named"students" to verify whether the student is a valid user. The "students"
database contains two tables named "login_pssword" and “marks”. The
login_pssword table has three fields “Student_Id”,"login" and"password”.
Check if the user name and passwords exist. If it exists print the message
"Thank you for logging in". If the password or login is not in the database,
display the alert message "wrongpassword and/or login please try again".
The “marks” table has five fields: student_Id, course_name, first_mark,
second_mark, Final_mark.

3)if a valid user logged in, give him/her two choices:

1. Add a new student
2. Remove a student

Design two different forms, one for each choice above to enable the student to perform the choice he/she selected.

the header code :-

XML

<html> <head> <script type = "text/javascript">
Function validate(){
     Winow.event.returnvalue = false;
     If ((f1.login.value == "") || (f1.password.value ==""))
                     alert("you must enter your name and password");
     else
             window.event.returnvalue = true;
         }
</script> </head> <body>
<form  id ="f1"  action = "validate.php"   method = "post" onsubmit ="validate()">
User Name <input  type ="text"  name = "login"/> <br />
Password <input  type ="password" name ="password"/> <br />
<input type = "submit"  value ="login"/>
</form> </body> </html>

Here is the complete code without ajax functionality. You didn't mention in the question if you wanted to display result without loading the php page.The login.html could looks like this:

HTML

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 
<html>
<head>
<script type = "text/javascript">

JavaScript

function validate(){
    if((f1.login.value == "") || (f1.password.value == ""))
    {
        alert("you must enter your name and password");
	return false;
    }
    else
    {    
	return true;
    }
}

HTML

</script>  
</head> 
<body>
<form  id ="f1"  action = "validate.php" method="post" onsubmit ="return validate(this);">
User Name <input  type ="text"  name = "login"/> <br />
Password <input  type ="password" name ="password"/> <br />
<input type = "submit"  value ="login"/>
</form> 
</body> 
</html>

The validate.php could look like this:

PHP

<?php
// fetching username and password
$userName = $_REQUEST["login"];
$userPassword = $_REQUEST["password"];
	
// using regular expressions to evaluate username
if(preg_match("/^[a-zA-Z][a-zA-Z0-9_]+$/", $userName, $matches)	)
{
    CheckWithDatabase($userName,$userPassword);
}
	
function CheckWithDatabase(&$usr, &$pw)
{
    // connecting to the database 
    mysql_connect("localhost", "userleon", "Pa55word") or die(mysql_error()); 
    mysql_select_db("students") or die(mysql_error()); 
    $data = mysql_query("SELECT login, password FROM login_password") or die(mysql_error());  
    while($info = mysql_fetch_array( $data )) 
    { 
         if( ($usr == $info['login']) && ( $pw == $info['password'] ))
	{
            echo "Thank you for logging in";
            // two choices offered on successful login
            echo "<form><input type=\"radio\" name=\"choice\" value=\"Add a new student\">Add a new student<br/><input type=\"radio\" name=\"choice\" value=\"Remove a student\"/>Remove a student</form>";
	}
	else
	{
            // GO BACK link
            echo "<a href=\"javascript:history.go(-1)\">GO BACK</a>";
            // javascript displays message
            echo "<script type=\"text/javascript\">alert(\"wrongpassword and/or login please try again\");</script>";
	}
    } 
}
?>

Hope it answers your question Smile | :)

follow me on twitter @leon_developer

modified 25-Nov-12 20:15pm.

Well done, you just did this guy's homework for him. Or worse, this guy is actually a paid programmer and you just did his work for which he's getting paid.

I am new here.How else should I answer questions?

Look for ones which are BLATANT homework or "send me codez im clueless", and move on to the next one.

Being new here and with good knowledge to help people is great and we welcome you to the community.
Like mentioned already by Jamie, we don't like blatant homework answers to be answered with complete code answers like you gave here. The reason is that we want the students who come here for help to learn how to develop things properly. No one learns anything when a blatant gimme-codez homework question is answered in full as you have. The OP is simply going to copy/paste your solution as their homework solution, get the marks, and learn nothing about the process of arriving at that solution. If you are already a professional developer, would you like to hire this individual to work with/for you? I doubt it and I know I don't want to. The way to answer questions like this if you feel so compelled is to lead them down the right path to a solution while still getting them to make the decisions and write the code necessary. That way every one is a winner. Again, cheers and welcome to CP.

I wasn't, now I am, then I won't be anymore.

Leon Munir ... thanks 4 u