How to make cells show blank based the cell to the left

I am trying to build a spread sheet for work, a crude CRM tool and I am now at the point where I can do extremely basic conditional formatting but building workable formulas is proving hard:

Problem Number 1:

1. I have a cell called 'number of days' it is the cell that captures the date difference between the date a sales engineer does a site visit, and the date a quote is raised -

When a quote is needed I have created a conditional format that changes the colour of a cell for the entry of the 'quote number', the next cell will have the date the quote is raised, then the next cell is for the number of days between the site visit and the quote being raised, my question is:

If there is no quote, then the conditional formatting doesn't get enabled which is perfect, but how do I make the cells that WON'T have a date in them not do the calculation for the date difference and remain totally blank

Temp CRM Excel Test Tool v3.xlsxHi Tony Thanks

I have the dates formats ok, I think, frankly I am a novis to Excel and trying to learn as much as possible about Excel and VB as soon as possible,

I have attached an extract of my Sales Activity and CRM combined tool that I have built so far, and I would appreciate an advice on more functionality

Or if anyone can advise what to read, research I just want to learn, but have no idea where to start to get on my way to being a VBA expert one day.

Columns U and V are ones that need to react when a quote drop down is selected in column L (which triggers conditional formatting of column T, which is what I wanted, but if a quote isn't needed, I don't need to see the date or days lapsed since sales activity...I trust that make more sense, my apologies if I have some across vague but all new to me.

Originally Posted by Tony Valko

OK, if a quote isn't needed then how do we know that? There is not a selection for that in the drop down list.

Hi Tony

The spread sheet is filled in by an admin clerk from info from the sales engineers manual call sheets and dependant in the outcome of the call one of the drop down choices will be relevant at worse case it would be the last one

I have I think used the icons to give some sort of visual scoring to the first part of the call record

Any advice you can give is more than welcome

Cheers

Scott