Mega Code Archive
Get a substring index
<![CDATA[
< HTML>
<HEAD>
<SCRIPT language="JavaScript">
<!--
function myFunction()
{
var email_add=window.prompt("What is your e-mail address?","");
if (email_add.indexOf("@") == -1)
{
window.alert("You need an '@' symbol in your address, please try again.");
}
if (email_add.indexOf(".") == -1)
{
window.alert("You need a '.' symbol in your address, please try again.");
}
if ( (email_add.indexOf("@") != -1) && (email_add.indexOf(".") != -1) )
{
document.write("Thanks!");
}
}
//-->
</SCRIPT>
</HEAD>
<BODY>
<FORM>
<INPUT type="button" value="Click to enter an e-mail address" onClick="myFunction();">
</BODY>
</HTML>
]]>