Validation script for Email Id

[Xan]

i need java script to validate email account .as when I enter one email address for which , i have to validate the mail id, i am unable to validate.so please some one can help me to do this thing ?

[Reegan]

<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>

[Modifier]

function validateEmail(strEmail)

{



var at="@"

var dot="."

var lat=strEmail.indexOf(at)

var lstr=strEmail.length var

ldot=strEmail.indexOf(dot)

if (strEmail.indexOf(at)==-1)

{

alert("Invalid E-mail ID")

return false

}

if (strEmail.indexOf(at)==-1 || strEmail.indexOf(at)==0 || strEmail.indexOf(at)==lstr)

{

alert("Invalid E-mail ID")

return false

}

if (strEmail.indexOf(dot)==-1 || str.indexOf(dot)==0 || strEmail.indexOf(dot)==lstr)

{

alert("Invalid E-mail ID")

return false

}

if (strEmail.indexOf(at,(lat+1))!=-1)

{

alert("Invalid E-mail ID")

return false

}

if (strEmail.substring(lat-1,lat)==dot || strEmail.substring(lat+1,lat+2)==dot)

{

alert("Invalid E-mail ID")

return false

}

if (strEmail.indexOf(dot,(lat+2))==-1)

{

alert("Invalid E-mail ID")

return false

}

if (strEmail.indexOf(" ")!=-1)

{

alert("Invalid E-mail ID")

return false

}

return true

}