Help with Functions!!!

I am learning about functions. For some reason the scripts work as individual pieces but when placed in a function and run nothing happens. Any help would be greatly appreciated. Here is what I have so far:

#Clears the screen

cls

#Generates a prompt that asks the user to input which computer to access

$computer= Read-Host "Enter the computer name:"

#Create a function that list the software installed on the computer specified by input argument

function getSoftwareInfo ($softwareInfo) {

#Gets the Programs installed on the computer

$softwareInfo = gwmi Win32_Product -computername $computer | Sort-Object Vendor, Name | Format-Table Vendor, Name

}

#Create a function that lists the free disk space and percentage of disk space used on the computer

function diskCheck {

#Gets the freespace of the C: Drive

$freeSpace = gwmi -class win32_logicaldisk -computername $computer  | where {$_.deviceid -eq"C:"} | select-object {$_.freespace / 1GB}

#Gets the total space of the C: Drive

$totalSpace = gwmi -class win32_logicaldisk -computername $computer | where {$_.deviceid -eq "C:"} | select-object {$_.size / 1GB}

#Gets percentage of disk space used

$percentUsed = (($totalSpace - $freeSpace)/$totalSpace) * 100

}

#calls the functions

getSoftwareInfo

diskCheck

#Create readable texts for both functions

$installed = "The programs that are installed in the " + $computer + " are as follows: " + $softwareInfo

$diskfree = "Free space available on C: drive:" + $freeSpace +" GB"

$diskused = "Percent of disk space used on C:" + $percentUsed +"%"

#Exports softwareInfo to CSV file

Export-Csv -path C:\Scripts\Computer_Software.csv -inputObject $installed

#Exports diskCheck to CSV file

Export-Csv -path C:\Scripts\Computer_hdspace.csv -inputObject $diskfree, $diskused

#Writes output to the screen

Write-Host $installed

Write-Host $diskfree

Write-Host $diskused