You should modify your design so that any text is entered in a separate text field so that this field either contains a number or is empty.
You can select your field while in layout mode and use the inspector (filemaker 11) or Format | Number... (Older versions of filemaker) to establish a data format with a fixed number of decimals--1 in your case--to make sure 34 is displayed as 34.0.
Ive created a new field like you said. Iam trying to do a calcultation for the LOQ fields that would set the field depending on what was entered in the result field. but i keep getting LOQ no matter what result is entered
If ( Toxin Type = "ASP" & ToxinResult < "1.25"; "LOQ")
what Iam really trying to achive is this
Toxin = DSP & Toxin Result < 10 = LOQ
Toxin = ASP & Toxin Result < 1.25 = LOQ
Toxin = PSP & Toxin Result < 10 = LOQ
The ampersand (&) is an operator that "glues together" (concatenates) text. You need to use the AND logical operator instead and a case function in place of your If function. You also need to remove the quotes from around your numbers so they are evalutated as numbers instead of text.
Case ( Toxin Type = "ASP" and ToxinResult < 1.25 ; "LOQ" ;
Toxin Type = "DSP" and ToxinResult < 10 ; "LOQ" ;
Toxin Type = "PSP" and ToxinResult < 10 ; "LOQ"