Need script for Widow/Orphan control

Yatani's script is an elegant solution; however, I might be tempted to choose Structure > EDD > Export Element Catalog as EDD. Then set the first and last paragraph rules to keep with next and keep with previous, respectively, for the sequential list element. You could use File > Import > Element Definitions to import this "special" EDD when you are doing your PDF publishing.

Hi,
Manually overriding paragraph formatting should not be used in structured documents, as it can lead to confusion in future revisions.
However, if you must do so, the following script might help:

#target framemaker
/*
    Finds the first and last elements in a sequential list and overrides paragraph formatting
*/

var doc = app.ActiveDoc;
var elements = doc.MainFlowInDoc.GetText (Constants.FTI_ElementBegin);

for (var i=0;i<elements.length;i++){
    // Enter the name of a sequential list element defined in your EDD
	if (elements[i].obj.ElementDef.Name == "Seqlist"){
        f_changePgfProps (elements[i].obj.FirstChildElement);
        f_changePgfProps (elements[i].obj.LastChildElement);
    }
}

function f_changePgfProps (ele){
    // Modify the script as needed
    var childEles = ele.GetText (Constants.FTI_ElementBegin);
    for (var i=1;i<childEles.length;i++){
        childEles[i].obj.TextRange.beg.obj.KeepWithPrev = true;
    }
}