Sometimes, I need to write hotel reservation form with PHP. Honestly, it’s kinda simple and not rush at all. But our major challenge is spam bots, and think about how to prevent nobody can send spam message to our reservation form. For this case, we can prevent in only 2 way. 1) is Image Captcha and 2) is check referer page. For 2) solution is here.
$path_parts = pathinfo($_SERVER['HTTP_REFERER']);
if($path_parts['basename'] == “reservation.html”)
For email validation, we don’t need to feel complicated. And, we don’t want our mail server will be over-loaded for the case of invalid email address. How to prevent? Don’t worry.
Write following code between <head></head>
<script language = “Javascript”>
function echeck(str) {
var at=”@”
var dot=”.”
var lat=str.indexOf(at)
var lstr=str.length
var ldot=str.indexOf(dot)
if (str.indexOf(at)==-1){
alert(“Invalid E-mail ID”)
return false
}
if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
alert(“Invalid E-mail ID”)
return false
}
if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
alert(“Invalid E-mail ID”)
return false
}
if (str.indexOf(at,(lat+1))!=-1){
alert(“Invalid E-mail ID”)
return false
}
if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
alert(“Invalid E-mail ID”)
return false
}
if (str.indexOf(dot,(lat+2))==-1){
alert(“Invalid E-mail ID”)
return false
}
if (str.indexOf(” “)!=-1){
alert(“Invalid E-mail ID”)
return false
}
return true
}
function ValidateForm(){
var emailID=document.frmSample.txtEmail
if ((emailID.value==null)||(emailID.value==”")){
alert(“Please Enter your Email ID”)
emailID.focus()
return false
}
if (echeck(emailID.value)==false){
emailID.value=”"
emailID.focus()
return false
}
return true
}
</script>
Write this code below of <body>
<form name=”frmSample” method=”post” action=”#” onSubmit=”return ValidateForm()”>
<p>Enter an Email Address :
<input type=”text” name=”txtEmail”>
</p>
<p>
<input type=”submit” name=”Submit” value=”Submit”>
</p>
</form>
