How can I use jQuery to make an input readonly?

Question

I have the following input:

How c

Answer 1

simply add the following attribute

// for disabled i.e. cannot highlight value or change
disabled="disabled"

// for readonly i.e. can highlight value but not change
readonly="readonly"

jQuery to make the change to the element (substitute disabled for readonly in the following for setting readonly attribute).

$('#fieldName').attr("disabled","disabled") 

or

$('#fieldName').attr("disabled", true) 

NOTE: As of jQuery 1.6, it is recommended to use .prop() instead of .attr(). The above code will work exactly the same except substitute .attr() for .prop().