diff --git a/common.R b/common.R
old mode 100755
new mode 100644
index 7414748..1f1bf96
--- a/common.R
+++ b/common.R
@@ -3,6 +3,7 @@
 # Taha Ahmed, Jan 2011
 
 # CONTENTS
+# >>>> ProvideSampleId
 # >>>> ConvertRefPot
 # >>>> Celsius2Kelvin
 # >>>> Kelvin2Celsius
@@ -12,6 +13,34 @@
 
 
 
+##################################################
+################ ProvideSampleId #################
+##################################################
+ProvideSampleId <- function (fullpathwithfilename) {
+     ### OBS! Only very rudimentary error-checking.
+     ### If the filename is formatted as \w*-\w*-\w*, we use the middle segment, 
+     ### otherwise we use the whole string (excluding the extension)
+     # Extract the name of the parent directory of the datafilename argument
+     substrateid <- basename(dirname(fullpathwithfilename))
+     # Extract the name of the method from the filename-part
+     # First split the filename over all hyphens
+     nameparts <- strsplit(basename(fullpathwithfilename), "-")[[1]]
+     # If the number of nameparts exceed 3, save the whole filename as methodid, otherwise use the middle part
+     if (length(nameparts) > 3) {
+        # We need to lose the file extension from the last namepart
+        nameparts[length(nameparts)] <- strsplit(nameparts[length(nameparts)], "\\.")[[1]][1]
+        methodid <- paste(nameparts, collapse = "-")
+     } else {
+        methodid <- nameparts[2]
+     }
+     # Make an informative sampleid
+     sampleid <- paste(substrateid, methodid, sep = "-")
+     #
+     return(sampleid)
+}
+
+
+
 ##################################################
 ################# ConvertRefPot ##################
 ##################################################