What is the best regex to check if there is a string inside another string?

This doesn't work:

var regex:RegExp = new RegExp("/^.+" + myString + ".+$/");

Thanks Greg your code is fine.

However I just can't seem to get these regex to work in my other code:

var st:String = addcurrencyInput.text;
if(addcurrencyInput.text.length == 0){
Alert.show("You cannot add a blank currancy");
}
else if(!st.search(new RegExp("/^[0-9]+$/"))){
Alert.show("The currancy may only contain alphabetical characters");
}
else{
myService.addCurrency(addcurrencyInput.text);
}

the following line never gets excecuted regarless of the text inside st

Alert.show("The currancy may only contain alphabetical characters");

else if(st.search(regex) == -1)

If the search fails, the return value is -1, not false or 0.

Dude you have made me a very happy man, I was worried about my boss getting impatient

Just remember to always check the FB3 help sys for relevant aspects of the
problem at hand. I checked the return value for the search method of the String
class. This is often how I solve these posts for people.