AJAX ASP Example

AJAX is used to create more interactive applications.

The following example will demonstrate how a web page can communicate with a web server while a user type characters in an input field:

Start typing a name in the input field below:

In the example above, when a user types a character in the input field, a function called showHint() is executed. The function is triggered by the onkeyup event.

<form> First name: <input type="text" onkeyup="showHint(this.value)"> </form> <script>

</script>

First, check if the input field is empty (str.length == 0). If it is, clear the content of the txtHint placeholder and exit the function. However, if the input field is not empty, do the following:

Create the function to be executed when the server response is ready Send the request off to an ASP file (gethint.asp) on the server Notice that q parameter is added gethint.asp?q="+str The str variable holds the content of the input field The ASP File - "gethint.asp" The ASP file checks an array of names, and returns the corresponding name(s) to the browser: <% response.expires=-1 dim a(30) 'Fill up array with names a(1)="Anna" a(2)="Brittany" a(3)="Cinderella" a(4)="Diana" a(5)="Eva" a(6)="Fiona" a(7)="Gunda" a(8)="Hege" a(9)="Inga" a(10)="Johanna" a(11)="Kitty" a(12)="Linda" a(13)="Nina" a(14)="Ophelia" a(15)="Petunia" a(16)="Amanda" a(17)="Raquel" a(18)="Cindy" a(19)="Doris" a(20)="Eve" a(21)="Evita" a(22)="Sunniva" a(23)="Tove" a(24)="Unni" a(25)="Violet" a(26)="Liza" a(27)="Elizabeth" a(28)="Ellen" a(29)="Wenche" a(30)="Vicky" 'get the q parameter from URL

end if end if next end if 'Output "no suggestion" if no hint were found 'or output the correct values if hint="" then response.write("no suggestion")

end if %>