checking if variable exists code

Discussion in 'Javascript' started by wg, Oct 24, 2005.

  1. wg

    wg Guest

    Hey,

    Can someone show my how to change the code below to check to see if a
    variable exists rather than if the variable contains an empty string.




    if (document.form.regionselection.value == "") {
    missinginfo += "\n - Region";
    }

    Thanks!
    Wayne
     
    wg, Oct 24, 2005
    #1
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  2. wg

    Ivo Guest

    This code checks a form element, not a genuine variable as such. To check if
    a form element exists, you simply test if its name occurs in the form
    elements collection, like so:

    if ( document.form.regionselection ) {
    // element exists, now check its value
    }

    or even betterr:

    if ( document.forms.form.elements.regionselection ) {

    This is assuming your form has id="form" (I'd chose a less confusing name
    btw).

    hth
    ivo
    http://4mui.com/web/javascript/
     
    Ivo, Oct 24, 2005
    #2
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