code: public static boolean call(PageContext pc, String type, Object value) throws ExpressionException {
  	type = type.trim();
  
  	if ("range".equalsIgnoreCase(type)) throw new FunctionException(pc, "isValid", 1, "type", "for [range] you have to define a min and max value");
  
  	if ("regex".equalsIgnoreCase(type) || "regular_expression".equalsIgnoreCase(type))
  	    throw new FunctionException(pc, "isValid", 1, "type", "for [regex] you have to define a pattern");
  
  	return Decision.isValid(type, value);
      }
docs: check for many diff types
  
  @param pc
  @param type
  @param value
  @return
  @throws ExpressionException