onBeforeFormatChange

fires before cell format is changed

boolean onBeforeFormatChange(number row,number column,string format,string oldFormat, [string page] );

row

numberrow ID column

numbercolumn ID format

stringnew format of the cell oldFormatstringold format of the cell pagestringthe name of the sheet

boolean

returning false will prevent format changing

$$("ssheet1").attachEvent("onBeforeFormatChange",function(row,col,format,oldF,page){
    // handler code here
    return true;
});

Details

The event is not called for pasting copied data. Use onBeforePaste instead.