open a new window

To open a new window, you will need to use yet another ready-made JavaScript function. Here is what it looks like:

window.open('url to open','window name','attribute1,attribute2')

This is the function that allows you to open a new browser window for the viewer to use. Note that all the names and attributes are separated with a comma rather than spaces. Here is what all the stuff inside is:

1. 'url to open'
   This is the web address of the page you wish to appear in the new window.

2. 'window name'
   You can name your window whatever you like, in case you need to make a reference to the window later.

3. 'attribute1,attribute2'
   As with alot of other things, you have a choice of attributes you can adjust.

Email address validation

/**
* DHTML email validation script. Courtesy of SmartWebby.com (http://www.smartwebby.com/dhtml/)
*/

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
}

The JavaScript has two functions:

• Function echeck is used to verify if the given value is a possible valid email address. This function thus simply makes sure the email address has one (@), atleast one (.). It also makes sure that there are no spaces, extra '@'s or a (.) just before or after the @. It also makes sure that there is atleast one (.) after the @.
  
  
• Function ValidateForm is used to make sure that the email field is not blank and that it is a valid email address on form submission.