pre-defined functions in LR

Points to note with web_url and web_link:

■web_url is not a context sensitive function while web_link is a context sensitive function. Context sensitive functions describe your actions in terms of GUI objects (such as windows, lists, and buttons). Check HTML vs URL recording mode.
■If web_url statement occurs before a context sensitive statement like web_link, it should hit the server, otherwise your script will get error’ed out.
■While recording, if you switch between the actions, the first statement recorded in a given action will never be a context sensitive statement.
■The first argument of a web_link, web_url, web_image or in general web_* does not affect the script replay. For example: if your web_link statements were recorded as
view sourceprint?
web_link("Hi There",

"Text=Hello, ABC",

LAST);
Now, when you parameterize/correlate the first argument to

view sourceprint?
web_link("{Welcome to LearnLoadRunner}",

"Text=Hello, ABC",

LAST);
On executing the above script you won’t find the actual text of the parameter {Welcome to Learn LoadRunner} instead you will find {Welcome to Learn LoadRunner} itself in the execution log. However to show the correlated/parameterized data you can use lr_eval_string to evaluate the parameter.