Many thanks for everyone's replies. A number of points have been raised which I'll try to address:
The settings of ZERO and EQNULL had no effect in any combination of off or on - except that I got different error message - but I always got a zero in the result and never a null. Bernie, you said it worked for you so could you please show me the syntax you used for the second argument. I've tried both -0- and null both enclosed in quotes and not. In the process of checking these alternatives I also got strange messages about not being able to open the designer while a form is running - when there was no form running and also about not having enough dynamic space to process the expressions. Eventually R:Base hung (rather than crashing). I'm using v6.5++ Windows (32-bit) U.S. Version, Build: 1.84xRT03 of Win98SE. Here's the full expression copied and pasted from the form: v1AgeNext = (ifnull(Birth1day, 0, ( (INT( (.#Date - Birth1day) / 365 )) + ) )) v1AgeNext is defined as an integer and the column Birth1day is defined as a date. Arg2 is currently set to zero so that I get no errors. This works but, naturally, returns 0 when Birth1Day is null. All these fail: v1AgeNext = (ifnull(Birth1day, -0-, ( (INT( (.#Date - Birth1day) / 365 )) + 1) )) v1AgeNext = (ifnull(Birth1day, '-0-', ( (INT( (.#Date - Birth1day) / 365 )) + 1) )) v1AgeNext = (ifnull(Birth1day, null, ( (INT( (.#Date - Birth1day) / 365 )) + 1) )) v1AgeNext = (ifnull(Birth1day, 'null', ( (INT( (.#Date - Birth1day) / 365 )) + 1) )) v1AgeNext = (ifnull(Birth1day, , ( (INT( (.#Date - Birth1day) / 365 )) + ) )) Razzak, I happened to be using Sans Serif, Regular, size 7 so I changed the size to 8 and still get the same effect in my database. So I went to ConComp and tried there and got the same thing. I've taken an image of the result which I will send to you privately rather than fill the list-user's e-mail up with a big file. All I changed was the date format and extended the date fields on the form. Regards, Alastair. A D B Burr, St. Albans, UK
