ActionScript 2.0 Language Reference - Adobe Help and Support

Example
The following example creates a text field called my_txt and assigns the text dog@house.net
to the field. The indexOf() method is used to find the first occurrence of the specified
symbol (@). If the symbol is found, the specified text (between the index of 0 and the symbol)
replaces with the string bird. If the symbol is not found, an error message is displayed in the
Output panel.
this.createTextField("my_txt", this.getNextHighestDepth(), 10, 10, 320,
22);
my_txt.autoSize = true;
my_txt.text = "dog@house.net";
var symbol:String = "@";
var symbolPos:Number = my_txt.text.indexOf(symbol);
if (symbolPos>-1) {
my_txt.replaceText(0, symbolPos, "bird");
} else {
trace("symbol '"+symbol+"' not found.");
}
If your SWF file includes a version 2 component, use the version 2 components'
DepthManager class instead of the MovieClip.getNextHighestDepth() method, which is
used in this example.
restrict (TextField.restrict property)
public restrict : String
Indicates the set of characters that a user may enter into the text field. If the value of the
restrict property is null, you can enter any character. If the value of the restrict property
is an empty string, you cannot enter any character. If the value of the restrict property is a
string of characters, you can enter only characters in the string into the text field. The string is
scanned from left to right. A range may be specified using the dash (-). This only restricts user
interaction; a script may put any text into the text field. This property does not synchronize
with the Embed Font Outlines check boxes in the Property inspector.
If the string begins with ^, all characters are initially accepted and succeeding characters in the
string are excluded from the set of accepted characters. If the string does not begin with ^, no
characters are initially accepted and succeeding characters in the string are included in the set
of accepted characters.
Availability: ActionScript 1.0; Flash Player 6
TextField 1223