Hi,
I am making a script to validate email addresses.
I first used a regular expression.
Then, I checked if two or more symbols are next to each other using loops. However, my code doesn’t work.
Please help me out.
Thanks in advance!!!
<html>
<head>
<title>Validating email addresses using JavaScript</title>
<script type="text/javascript">
function validate()
{
var email = new RegExp("^[A-Z0-9a-z]{1}[A-Z0-9a-z|\\._]*[A-Z0-9a-z]{1}[@]{1}[A-Z0-9a-z]{1}[A-Z0-9a-z-\\.]*[A-Z0-9a-z]{1}[\\.]{1}[A-Za-z]{3,4}$","i");
var given = document.getElementById("email").value;
document.getElementById("email").value.toLowerCase();
var result = email.test(given);
if (result==false)
{
return false;
}
else
{
var num =0;
while (num<(given.length)-1 && num!=-1)
{
num = given.indexOf(".",num)
if (num>0 && (num<(given.length)-1))
{
if (given.charAt(num-1)=="." || given.charAt(num-1)=="-" || given.charAt(num-1)=="_" || given.charAt(num-1)=="@" || given.charAt(num+1)=="." || given.charAt(num+1)=="-" || given.charAt(num+1)=="_" || given.charAt(num+1)=="@")
{
return false;
}
}
else if (num==0)
{
if (given.charAt(num+1)=="." || given.charAt(num+1)=="-" || given.charAt(num+1)=="_" || given.charAt(num+1)=="@")
{
return false;
}
}
else if (num==(given.length)-1)
{
if (given.charAt(num-1)=="." || given.charAt(num-1)=="-" || given.charAt(num-1)=="_" || given.charAt(num-1)=="@")
{
return false;
}
}
if (num<(given.length)-1 && num!=-1)
{
num=num+1;
}
}
if (given.indexof("-",0)!=-1)
{
num =0;
while (num<(given.length)-1 && num!=-1)
{
num = given.indexOf("_",num)
if (num>0 && (num<(given.length)-1))
{
if (given.charAt(num-1)=="." || given.charAt(num-1)=="-" || given.charAt(num-1)=="_" || given.charAt(num-1)=="@" || given.charAt(num+1)=="." || given.charAt(num+1)=="-" || given.charAt(num+1)=="_" || given.charAt(num+1)=="@")
{
return false;
}
}
else if (num==0)
{
if (given.charAt(num+1)=="." || given.charAt(num+1)=="-" || given.charAt(num+1)=="_" || given.charAt(num+1)=="@")
{
return false;
}
}
else if (num==(given.length)-1)
{
if (given.charAt(num-1)=="." || given.charAt(num-1)=="-" || given.charAt(num-1)=="_" || given.charAt(num-1)=="@")
{
return false;
}
}
if (num<(given.length)-1 && num!=-1)
{
num=num+1;
}
}
}
if (given.indexOf("_",0)!=-1)
{
num =0;
while (num<(given.length)-1 && num!=-1)
{
num = given.indexOf("-",num)
if (num>0 && (num<(given.length)-1))
{
if (given.charAt(num-1)=="." || given.charAt(num-1)=="-" || given.charAt(num-1)=="_" || given.charAt(num-1)=="@" || given.charAt(num+1)=="." || given.charAt(num+1)=="-" || given.charAt(num+1)=="_" || given.charAt(num+1)=="@")
{
return false;
}
}
else if (num==0)
{
if (given.charAt(num+1)=="." || given.charAt(num+1)=="-" || given.charAt(num+1)=="_" || given.charAt(num+1)=="@")
{
return false;
}
}
else if (num==(given.length)-1)
{
if (given.charAt(num-1)=="." || given.charAt(num-1)=="-" || given.charAt(num-1)=="_" || given.charAt(num-1)=="@")
{
return false;
}
}
if (num<(given.length)-1 && num!=-1)
{
num=num+1;
}
}
}
}
}
</script>
</head>
<body>
<form method="post" action="doesnotexists.php" onsubmit="return validate()">
<input type="text" name="email"><br />
<input type="submit" value="Check">
</form>
</body>
</html>
```html4strict