how?

hello. i read from a text file a line like: "Key=$value" so, i do like: $lines = join('', file("myfile.txt")); echo $lines; // output= Key=$value Now how can i replace the values in the $lines variables? i want like: $value = "test"; echo $lines; and i want ouput like: Key=test any idea? -elias http://eassoft.cjb.net