It can be done using javascript.
Consider below form.
onSubmit event of Form is calling a javascript function ValidateForm
<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>
The javascript function ValidateForm is calling another function emailcheck to validate syntax of the email id.
<script language = "Javascript">
function emailcheck(str) {
var at="@"
var dot="."
var lat=str.indexOf(at)
var lstr=str.length
var ldot=str.indexOf(dot)
if (str.indexOf(at)==-1){
return false //if @ symbol is not there
}
if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
return false //if @ symbol available at starting or ending of email.
}
if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
return false //if "." is not available, or available at beginning or end of email.
}
if (str.indexOf(at,(lat+1))!=-1){
return false //if more one @ symbol available in email
}
if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
return false //if no letter is available between @ and "."
}
if (str.indexOf(dot,(lat+2))==-1){
return false
}
if (str.indexOf(" ")!=-1){
return false //if blank space available in email.
}
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 (emailcheck(emailID.value)==false){
emailID.value=""
emailID.focus()
return false
}
return true
}
</script>
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1 comment:
In case to check whether the symbols like /:; are avail
how to validate the email
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