ActionScript 2.0 Language Reference - Adobe Help and Support

list_txt.htmlText += "Track 2";
When you click a link, the MP3 sound file streams in Flash Player.
See also
htmlText (TextField.htmlText property)
Boolean function
Boolean(expression:Object) : Boolean
Converts the expression parameter to a Boolean value and returns a value as described in the
following list:
■ If expression is a Boolean value, the return value is expression.
■ If expression is a number, the return value is true if the number is not 0; otherwise the
return value is false.
If expression is a string, the return value is as follows:
■ In files published for Flash Player 6 and earlier, the string is first converted to a number.
The value is true if the number is not 0, otherwise the return value is false.
■ In files published for Flash Player 7 and later, the result is true if the string has a length
greater than 0; the value is false for an empty string.
If expression is a string, the result is true if the string has a length greater than 0; the value
is false for an empty string.
■ If expression is undefined or NaN (not a number), the return value is false.
■ If expression is a movie clip or an object, the return value is true.
Unlike the Boolean class constructor, the Boolean() function does not use the keyword new.
Moreover, the Boolean class constructor initializes a Boolean object to false if no parameter
is specified, while the Boolean() function returns undefined if no parameter is specified.
Availability: ActionScript 1.0; Flash Player 5 - Behavior changed in Flash Player 7.
Parameters
expression:Object - An expression to convert to a Boolean value.
Returns
Boolean - A Boolean value.
Example
trace(Boolean(-1)); // true
Global Functions 51