I'm attempting to select a part of a strint between 2 values, i've managed to get it working to about 90% but then get an error - 

```
SUBSTRING(TranText, CHARINDEX('x', TranText) + 1, LEN(TranText) - CHARINDEX('x', TranText) - CHARINDEX('/', REVERSE(TranText)))

```

The field it is querying is like so

> 
> Start Date : 01/02/2013 50 x 156.00/MX + 207.64
> 
> 
> 

with the desired result being 

> 
> 156.00
> 
> 
> 

Now I think the issue is because sometimes the X can have a space before or after it, or no space at all. It gets through about 114,000 rows before throwing

> 
> Invalid length parameter passed to the LEFT or SUBSTRING function.
> 
> 
> 

But am struggling to resolve.