[jQuery] How to access a field in a form

[bob]

Hi,
What is the best way to access a field in a form when I already have
an jQuery object referencing form.

function myFunction(formName, fieldName){

        var formjQueryObject = jQuery('#'+formName);


    var formField = jQuery("#"+formName+" [name='" + fieldName +
"']");
    or can I somehow utilize "formjQueryObject" and make field
selection faster?

}

<form name="myForm_1" id="myForm_1" >
        <input type="text" name="login" />

<form name="myForm_2" id="myForm_2" >
        <input type="text" name="login" />


myFunction("myForm1", "login");