I am trying to understand something. If I do the following

```
 if( $("#fileOne")[0].files[0].type != 'application/pdf') {
        errors.push("- Please upload correct document type");
    }

```

It works as it should do...If I dont upload a PDF, I get an error, if I do, I dont get an error. However, if I change it to the following

```
if(  $("#fileOne")[0].files[0].type != 'image/bmp' ||
            $("#fileOne")[0].files[0].type != 'image/jpeg' ||
            $("#fileOne")[0].files[0].type != 'image/pjpeg' ||
            $("#fileOne")[0].files[0].type != 'image/png' ||
            $("#fileOne")[0].files[0].type != 'image/tiff' ||
            $("#fileOne")[0].files[0].type != 'application/pdf') 
{
    errors.push("- Please upload one of the valid document types");
}

```

If I upload a PDF or any other file listed there, it still throws the error. It seems that adding all the extra types seems to make it fail.

Is there any reason for this?

Thanks