Thanks for replying! I have made the following changes, but still no luck : /

Code:
#include <iostream>
#include <fstream>
#include <string>
#include <vector>

using namespace std;

class InventoryInfo  
{
        string InventoryID;
        string InventoryDesc;
        string InventoryCost;
		string FileName;

public:
		InventoryInfo() {InventoryID=""; InventoryDesc=""; InventoryCost="";}
        InventoryInfo(string ID, string Desc, string Cost)
		{
			InventoryID=ID;
			InventoryDesc=Desc;
			InventoryCost=Cost;
		}
 
		void SetID(string ID) {InventoryID=ID;} 
		void SetDesc(string Desc) {InventoryDesc=Desc;}
		void SetCost(string Cost) {InventoryCost=Cost;}

		string GetID() {return InventoryID;}
		string GetDesc() {return InventoryDesc;} 
		string GetCost() {return InventoryCost;}
};

class FileAccess  
{
        string FileName;
		int Size;

public:
        FileAccess();
        FileAccess(string);

		void WriteToFile();
}

FileAccess::FileAccess()
{
        FileName = "Temp File";
        Size = 0;
}

FileAccess::FileAccess(string FName)
{
        FileName = FName;
        Size = 0;
}

void Fill(vector<InventoryInfo>& iInfo);
void Show(vector<InventoryInfo> iInfo);
void Find(vector<InventoryInfo> iInfo);
void Remove(vector<InventoryInfo>& iInfo);

int main()
{
        vector<InventoryInfo> iInfo;  //Creates an object...vector of strings...

		Fill(iInfo);
        Show(iInfo);
		Remove(iInfo);
		Show(iInfo);
		Find(iInfo);
		WriteToFile(iInfo);
}

void Fill(vector<InventoryInfo>& iInfo)
{
		cout<<"*** Add item ***"<<endl;

		string ID, Desc;
		string Cost;

		for(;;)
		{
			cout<<"\n=================================================================="<<endl;
			cout<<"Please enter an item ID, type 'stop' to cancel"<<endl;
			cout<<"> ";
			getline(cin, ID);
			if(ID=="stop")
				break;

			cout<<"\nPlease give a description of the item"<<endl;
			cout<<"> ";
			getline(cin, Desc);

			cout<<"\nWhat is the cost of the item?"<<endl;
			cout<<"> $";
			getline(cin, Cost);
			cout<<"=================================================================="<<endl;

			InventoryInfo Value0;
			Value0.SetID(ID);
			Value0.SetDesc(Desc);
			Value0.SetCost(Cost);

			iInfo.push_back(Value0);
		}
}

void Show(vector<InventoryInfo> iInfo) // reference!
{
		cout<<"\n*** Item Inventory ***"<<endl;

		vector<InventoryInfo>::iterator AccessInventory; //Sets up an iterator...

		for( AccessInventory = iInfo.begin() ; AccessInventory != iInfo.end() ; ++AccessInventory)
		{
			cout<<"\n=================================================================="<<endl;
			cout<<"> Item ID: "<<AccessInventory->GetID() << endl; // use iterator...
			cout<<"> Item description: "<<AccessInventory->GetDesc() << endl;
			cout<<"> Item cost: $"<<AccessInventory->GetCost() << endl;
			cout<<"=================================================================="<<endl;
		}
}

void Find(vector<InventoryInfo> iInfo)
{
		string Search;

		cout<<"\nPlease enter item ID to search: "<<endl;
		cout<<"> ";
		getline(cin, Search);

		vector<InventoryInfo>::iterator AccessInventory; //Sets up an iterator...

		for( AccessInventory = iInfo.begin() ; AccessInventory != iInfo.end() ; ++AccessInventory)
		{
			if(AccessInventory->GetID()==Search)
			{
				cout<<"\n=================================================================="<<endl;
				cout<<"> Item ID: "<<AccessInventory->GetID() << endl; // use iterator...
				cout<<"> Item description: "<<AccessInventory->GetDesc() << endl;
				cout<<"> Item cost: $"<<AccessInventory->GetCost() << endl;
				cout<<"=================================================================="<<endl;
				return;
			}
		}
		cout<<"\nItem ID not found, please try again..."<<endl;
		return;
}

void Remove(vector<InventoryInfo>& iInfo)
{
		string Remove;

		cout<<"\nPlease enter item ID you wish to delete: "<<endl;
		cout<<"> ";
		getline(cin, Remove);
		cout<<"\nItem inventory updated!"<<endl;
	
		vector<InventoryInfo>::iterator AccessInventory;
 
        for(AccessInventory = iInfo.begin() ; AccessInventory != iInfo.end() ; ++AccessInventory)
		{       
			if(AccessInventory->GetID() == Remove)  
			{
				iInfo.erase(AccessInventory);
				return;
            }
		}
        cout<<"\nItem ID not found, please try again..."<<endl;
		return;
}

void FileAccess::WriteToFile()
{
		fstream OutFile(FileName.c_str(), ios::out);
	
		vector<InventoryInfo>::iterator AccessInventory; //Sets up an iterator...

		for( AccessInventory = iInfo.begin() ; AccessInventory != iInfo.end() ; ++AccessInventory)
		{
			OutFile<<AccessInventory->GetID()<<endl;
			OutFile<<AccessInventory->GetDesc()<<endl;
			OutFile<<AccessInventory->GetCost()<<endl;
		}
		OutFile.close();
}