The StrToFloat function converts a String into a Float data type.

If the value that is in the String contains currency formatting, then use the FloCurrStrToFloat function instead.

StrToFloat will accept the decimal place full-stop (.) only as the decimal symbol, regardless of any Windows setting.

If the String does not contain a numeric value, then an error will occur. In this case you could use a Try...Except block to handle the error and provide a default value. 

Declaration: Function StrToFloat( const S : string) : Extended

A simple example follows.

procedure OnMapEvent(var Value:Variant);
var
MyAmount : String;
begin
MyAmount := '123.3456';
//Value will be equal to 123.3456
Value := StrToFloat(MyAmount);
end;