String.prototype.replaceAll = function(
strTarget, // The substring you want to replace
strSubString // The string you want to replace in.
){
var strText = this;
var intIndexOfMatch = strText.indexOf( strTarget );

// Keep looping while an instance of the target string
// still exists in the string.
while (intIndexOfMatch != -1){
// Relace out the current instance.
strText = strText.replace( strTarget, strSubString )

// Get the index of any next matching substring.
intIndexOfMatch = strText.indexOf( strTarget );
}

// Return the updated string with ALL the target strings
// replaced out with the new substring.
return( strText );
}